The next patch is coming up and it's a little confusing what is coming in WotLK and what is coming with the next patch called "Echoes of Doom". I made this little thread with information taken from WoW-Europe and WotLKWiki to clarify things up.
New class spells and talents
You can now spec according to the revamped talent tree for every class.
Stormwind Harbor
You can visit this new structure already. In WotLK you can take the boat at this place to travel to Northrend.
Barbershops in capital cities
Customize a character’s look with a stylish haircut, a shave, and other trimmings.
You can see a preview of the new haircuts at
Barbershop - WotlkWiki - Wrath of the Lich King Information]
New zeppelin towers
These new towers which are located outside Orgrimmar and Undercity will give you access to Northrend once WotLK hits the stores.
Two brand-new Arenas
There will be two new arenas in the next patch. One is called Dalaran Arena and the other one Orgrimmar Arena.
Both of these new arenas have enviromental aspects in the game which (imo) make arena even more luck-based as it is now.
Dalaran Arena: Picture
This arena is located in the sewers. Each team starts in one pipe. At the start of the match water will push you out of the pipe to prevent camping. There is also another pipe in the arena from which water drops ocasionally, causing various line of sight issues.
Water levels will rise and fall around the edges of the arena throughout the match.
This arena is quite small, therefore mounts will not be allowed.
Orgrimmar Arena: Picture
As you can see on the picture there are various enviromental structures involved in this arena.
The two larger holes in the middle are elevators which will rise at the beginning of the map. The first 3 seconds of the game there will be spikes around the elevator so you cannot reach eachother inmediality.
During the match pillars will arise from the ground as set times, causing LoS issues.
The other objects on the floor can containt of Saws that will come out of the floor and damage you if you walk over it or a wall of spikes coming up.
Hunter pet skill revamp
Pet skill points are now availible for you to play around with. Your pet is no longer a meatshield but it can actually be useful!
New Inscription profession
Start collecting your herbs because the prices on it will skyrocket. With the new patch Inscription goes live and everyone wants to try it! Custumize your gear and skills with this wonderful new profession.
New user-interface options
There is also a new change to the mount and minipet system as most of you know already. You will now have a button on your interface which will bring up a list of all mounts/minipets you own. You no longer have to carry them in your inventory. You can, ofcourse, still hotkey your favourite mount.
There is also a Guild Calendar system, no more need for AddOns!
Achievement system
You can start unlocking achievements and achievements you have currently unlocked already will be automaticly awarded. Have fun with this new system, I personally think it's a great RPG element!
Honor and battleground marks
It is confirmed by several Blizzard employees that honor will not be reset. You can save up 75k honor before WotLK and spend it on rewards as soon as you hit level 80. The only thing is that the rewards will be significantly more expensive but who cares? This should give you a great (unfair) headstart over other players. I say start farming AV!