Quote from Blizzard staff
BLIZZCON
Dual-Spec system
* The dual-spec system will be introduced in a content patch. The goal is to let you switch specs very easily in raid, even between fights ! However it won't be possible to switch specs in the middle of an arena match.
* With dual-spec introduced in the game, there are also discussions about an Itemrack-like mod being introduced to the default UI
Group Flexibility
* There are 30 specs but only 25 spots in a raid. The class choice should be very flexible and the buff/debuff system overhaul was done to help with that. Cancelling a buff because a class wasn't available (like Shamans for Bloodlust) was not desirable.
* Most buffs now affect the whole raid and multiple classes can give them, however none of them will stack. You should get more types of buffs by bringing a fewer number of players and will be able to optimize them by bringing the right spec but it definitely won't be as necessary as it was in TBC. (Note : See Raidcomp [b]http://raidcomp.mmo-champion.com/[/b])
Tanking
* All the tanking classes are now suitable as a main tank and their threat has been greatly increased to make fights more fun, fights are now more about skills than dying because of a random aggro.
DEATH KNIGHT * The original idea behind the rune system was a totally customizable rune pool (like, 6 Unholy runes) but "it sucked". They changed it to what is it today (2 Runes of each type)
* Death Knights shouldn't be played like a metronome and is intended to be an interactive and reactive class.
* As a death knight, your talent trees are a good way to define "your style, but not your role". Devs want to bring this philosophy to other classes.
DRUID * Balance druids have been greatly improved and you shouldn't see a lot of OOMkins anymore. Their DPS is now on par with other DPS classes.
* Balance DPS looks pretty good now but developpers are keeping an eye on the survavibility
* Entangling roots was allowed indoor to give druids more crowd control ability in instances.
* Restoration were stuck in the HoT niche and were very limited in 5-mans or raids. Nourish is new flash heal-like spell added to solve this problem on single targets and Wild Growth was added to give them an AOE Heal.
* Druids were also given an OOC resurrection spell.
* Feral druids were decent at tanking and DPSing, but couldn't master any of these fields. In WotLK you can take all the bear talents to become a very good main tank, or all the cat talents to have a very high DPS.
* Feral mana is a known issue, and developpers don't want intellect on feral gear. This is being looked at
HUNTER * The hunter pet system was overhauled because it was "clumsy for new players".
* The shot rataion has been cleaned to make things easier for hunters and make them less reliant on mods or macros.
* Freezing shot was introduced to make pulls faster without having to deploy your traps on the ground each time.
MAGE * Frostfire Bolt is a way to achieve an elemental tree with mages, they should be able to deal both fire and frost damage
* Mage DPS looks pretty good now, there are still a few mana issues getting fixed very soon
* Living Bomb base damage will most likely be increased and the spell mechanics might be modified slightly. Overall, the 51-points talent weren't meant to be spammed and developpers want them to be situational
* Frost and Fire looks pretty balanced now, but Arcane needs a few more tweaks. Arcane needs to be more "mobile"
PALADIN * Paladins were decent off-tanks but not great main tanks, this is fixed in WotLK. Paladins should focus on protection gear instead of spell power.
* Holy Paladins were good healers but couldn't do much in encounters where players are required to move a lot, however they definitely don't want them as a HoT class.
* Retribution paladins are supposed to deal a decent amount of DPS without running out of mana.
* Retributions paladins have to be in control of their damage and shouldn't have to rely on lucky critical strikes to deal most of their damage
PRIEST * The goal with Shadowpriest is to make them a DPS class, not just a mana battery.
* Discipline priests should be viable raid healer.
* Mind sear was introduced to give priests another viable DPS ability.
* Class-specific racial abilities were cool, but the idea became got "old" with time. That's why racials have been revamped
ROGUE * AoE DPS was really needed and Fan of Knives was added to the game.
* Purchasable poisons and the buff of the dagger spec should help "reintroducing" them to the game.
* The goal is to have end-boss less immune to poisons and rogues less dependant of Windfury
SHAMAN * Totems are now physical and harder to dispell, have more life and last longer.
* Hex was added to give Shamans more crowd control ability, Riptide to improve their healing, and Lava Burst their spell DPS.
WARLOCK * Warlocks pets have been made more useful.
* The warlock rotation shouldn't be restricted to a shadowbolt spam, that's why Chaos Bolt was added.
* Affliction Tree is still too complicated and developpers are working on it. Developers definitely want it back as a raiding spec
* Pets should be easier to summon/switch and use.
WARRIOR * Protection spec has been revamped to make it cooler to play, mitigation talents now take a lot less points and will let you invest in a few other nice tools.
* In TBC, Arms was PvP and Fury the PvE spec, this will change in WotLK : Battle Stance, Overpower, and Rend have been improved. New fun abilities have been introduced like Bladestorm and Sudden Death, Fury obviously have Titan's Grip.
