If you could take something from one game and stick it in WoW...

[Lefaux]

Ingame Browser themed like the game just like in EVE.
Would make DKP checks etc. SO much easier

[Sarmifias]

A quest where you dress up as Garrosh and have to barter with local merchants to get max discounts.

I'm Warchief Garrosh, and this is my favorite store in the Valley of Honor.

I love this guy and his mass effect 2 refrences lol

But honestly id do something in reverse, id take every good aspect of WoW and stuff it into the new Dawn of War 40k MMO coming out so we can start off on a good foot.

[alex]

Gravity gun from HL2.

I would move whole dalaran and throw it into northrend sea.

[Litoru]

I would want a piece of Aion in the game, sometimes I just miss that game because the environment is so alive.

I'd also want more options to customize my character's face/hair (tattoos, make up, piercings, more hairstyles and such) and that they upped the grafics on the characters in general.
/seriousness off

A godly unbeatable boss that would rampage across the server!!! Like 80 man or 40 man or maybe a shit ton of people. make my day PLEASE!!!

EDIT: GIEF! That would've been so epic, especially if it was headed thowards one of the big cities D:

[Splenda]

An appearance tab type thing, where I can choose how I want my armor to look, regardless of what I'm actually wearing. Even if I can only do it out of combat, I'd love to stand around in Org or wherever and look how I please.

[Elunedra]

Guild housing !
less lagg in major city's ,

epicly costumiseable and awsome features like build in bartenders and a thone for your GM.