Old Dungeons in Cataclysm
The old dungeons are getting some love, including some new quests. (Source)
 
Leveling with a Healing spec
We are going to make leveling easier for healing specs. You still shouldn't expect to do anywhere near the damage of a dps spec though (otherwise, why would you ever level as dps?).
 
You can use your healing spec to use Dungeon Finder as you level. [...] But even if you don't use dungeons, you can level with a healer spec. I've done it a few times -- it's not super fast, but it's not horribly broken either, and it will be better in Cataclysm. (Source)
 
Pet scaling and Mastery bonus
We can make the pet damage scale with mastery even if they aren't getting the same benefit you are (because in many cases that won't make sense). (Source)
 
Not enough build choices in the new trees?
WoW shipped with trees roughly the size the ones Cataclysm will be and I don't recall a lot of players at the time thinking that there weren't enough choices.
 
In terms of pure numbers, the new trees offer fewer maximum number of combinations than the old ones. But many of the old combinations were not viable ones anyway. The new design is fewer meaningful choices rather than having lots of trivial (or even bad) choices. (Source)
 
Exponential inflation of stats
You're confusing relative to absolute effects in a couple of cases here. It is not harder to balance big numbers. Math works the same way on big numbers as it does on small numbers. It's harder to balance big numbers to small numbers, which might be a problem if we expected say level 85 characters to PvP against level 35 characters, but that's not how we design the game. It isn't important to us at all that level 75 characters can hold their own vs. level 80 characters. It's more fun to become more powerful as you level rather than see only slight improvements in your stats.
 
Fresh level 85 content won't be trivialized by level 85 characters until a new patch comes out, at which point it's not fresh content any longer.
 
The point I think has the most merit is your point A, but I think that one is a worthy sacrifice in order to be able to provide more content and a sense of progression to existing characters.
 
There's a magic number that we've found over time to feel satisfying to players, and that's about the 13 item level jump between tiers of content. When the numbers are less than that, players see for example their health only go up by 10 or 100 points, which doesn't feel meaningful. They don't feel rewarded for their efforts and have less interest in doing the quests or dungeons or the new PvP season. If players gain a level or two and still have trouble with that raptor that gave them a hard time before, then they don't feel like the process of improving their character is worth it. Everything else is derived for the need to have that meaningful jump. (Source)
 
 Hunter (Forums / 3.3.5 Talent Calculator)
Hunters in Cataclysm
Chimera vs. Arcane – Chimera should have a higher DPCT/damage than Arcane as a tradeoff for having a cooldown. You should be casting Chimera before Arcane in any situation where it's not on cooldown. There numbers may not be tuned quite right yet.
 
Serpent Sting – You’ll find it's not efficient to cast your damage-over-time on targets that die before Serpent Sting lasts the full duration. This is similar to other classes. Druids don’t use all of their bleeds on targets that die in 8 seconds; it's just not efficient. Chimera refreshing Serpent Sting is a bonus for fights that take longer, like boss fights or “epic” creatures. It isn’t factored into the “budget” of the ability, so don’t feel like you wasted a Chimera just because you couldn’t utilize the “refresh Serpent Sting” mechanic.
 
Tranq Shot – We want this to have a focus cost. There may be opportunities where you want to use two Tranqs in a row, and it's your decision if you want to do that or not. I think most Hunters dislike it having a focus cost because they feel their raid leaders may mandate them to dispel something on an encounter, and because they have to spend focus it sucks because you lose DPS. That's legitimate, but also the same kind of decision that a lot of other classes have to make.
 
Venoms – We hear you on some of their issues. We might try things like giving them some damage, reducing the focus cost, and / or have them last 5 minutes on PvE creatures. Again, shooting a Venom isn’t really ideal on targets that you kill quickly. You shouldn’t cast one on every trash mob, for example. That said, we don’t want them to become too “maintenance-y” on boss fights.
 
Aspects – We would like Aspect of the Fox to be as good as it can be, which we feel is 30%. Any higher than that and we lose the Steady Shot focus-generating gameplay. It seems that some hunters are, not surprisingly, somewhat turned off from doing less damage while moving as they are on live, but this is intended. A ranged class that can do almost as much damage moving as it can standing still is not going to be fair, and often is what restricts us from doing cool things with the class.
 
Trap Launcher – We'd like to take it off the GCD. (Source)
 
 
 Paladin (Forums / 3.3.5 Talent Calculator)
Holy Paladins in LK
I'm exaggerating slightly here, but our LK model for Holy paladins was that they could only do one thing well so they might as well be overpowered at it. We could essentially just balance incoming tank damage around outgoing paladin healing. The paladin niche was very small, so if they weren't good at single target and mostly tank healing, they'd be replaced. Yet because it was small, there wasn't much risk of overstacking them as healers.
 
That model worked okay but it ultimately wasn't what we wanted, so we're going to change it in Cataclysm as much as we can without all of the healers playing identically. You should feel more comfortable having a paladin heal the raid and a druid heal the tank than most groups typically do now. (Source)
 
Forbearance
It will be reevaluated. (Source)
 
 Warrior (Forums / 3.3.5 Talent Calculator)
Sunder Armor
Making Sunder do damage just felt too much like Devastate. [...] I've seen suggestions to have something you normally hit renew a Sunder. That might be the kind of thing we mess around with. (Source)
 
Enrage proc from damage done?
Is there any chance this means the talent Enrage in the fury tree will proc off of damage done instead of damage taken? It seems unlikely warriors will be able to pick up Wrecking Crew with the new talent system, so I think the fury signature Enrage should work the way fury does; dealing damage. Not taking it.  
It's possible, but Fury also has Bloodrage, Berserker Rage and Death Wish. If Enrage included AE damage it would proc a lot more in PvE too. Like I said above, we want Fury to be angry a lot, but not 100% of the time so we may need to tweak things to get to that point. (Source)
 
Enrage-linked attack (Source)
We are experimenting with an attack linked to enrage. Fury has a lot of ways to get angry now, and it has good synergy with their mastery and distinction from Arms.  
 
Please this, but don't consume the enrages. Requiring a rage to activate is fine, like GC said, fury warriors have lots of ways to get angry. But losing an 18% damage increasing enrage which we are balanced around having up 100% of the time is not worth an attack. Unless it is made so that it can only consume specific enrages (Blood Craze, Bloodthirst, etc.)
Yeah, I actually think it's cooler if the enrage is not consumed. When you give up damage over time for sudden damage, it turns out to be a math problem, and you can see lots of examples where we've ended up reverting or letting you talent out of a "consumes the charges" mechanic. If Fury isn't enraged 100% of the time (but isn't enraged 5% of the time either), and they have an attack that can only be used when enraged, but can be used frequently at that time, then you might have a pretty interesting rotation.  
 
Arms is a gladiator, Fury is half naked (Sorry. Don't hate me warriors!)
We view Arms as a soldier, like a career military infantryman. Think Gladiator. We view Fury as the wild berserker from up in the hills. Think Braveheart or Conan. It's easy to argue that bleeds or mobility fit one or the other depending on your point of view. Arms feels tactical (in the sense of having an answer for various situations) and Fury feels reckless. The Arms warrior has pet names for all his weapons, while the Fury warrior shows up for battle drunk and half clothed. (Source)

Arms is a gladiator, Fury is half naked (Sorry. Don't hate me warriors!)

Je viens de relancer mon abo sur wow(pause de 8mois environs), c'est quoi ce bordel sur les héroiques???    
Je mets mon démo 80 à jour, et je vois que les héroïques se résument à aoe tout le long sauf sur les boss....des tanks avec 50k de pv (à l'époque j'étais content de mes 35k avec mon dk tank   ), des insignes qui tombent à plus savoir quoi faire, des héroïques que l'on peux faire à l'infini avec le système de donjon aléatoire    
 
Franchement blizzard a fait de la merde là, en gros si on fait pas de raid(c'est mon cas, vu que j'ai pas de guilde pour le moment), ben on se fait plus que chier(le rerolliste aiguë saura la solution je crois...ou pas).
 
Y'aurait-il des personnes qui commencent à monter un perso de petit lvl, ou même vous connaisez des serveurs qui auraient pas trop avancer en terme de raid pve(genre encore sur ulduar)?

 
Drek Thar, serveur de péon avec son lot de chinois ^^...