Queueing next ability.

Q u o t e:
Anyway to disable this?

It’s not possible to disable the ability queue as it’s now part of how player abilities are handled on the server side. This was implemented as a counter to an extremely damaging form of exploitation which allowed players to (quite easily) avoid global cooldowns. As you can imagine it wasn’t something we could ignore. This new ability queue system prevents the exploit, while leaving gameplay as familiar as possible.

There are additional improvements in the works though to improve the feel of the new system, which include a slider that will allow players to tune their UI responsiveness according to their own ping and connection speeds. This specific improvement is currently planned to arrive before Cataclysm.

This new mechanic was initially announced on our Cataclysm beta forums, with many follow up posts that went into system clarifications, and some of the future improvements. All of which can be found in this thread: http://forums.worldofwarcraft.com/thread.html?topicId=26859116137&pageNo=11&sid=2000#214