Here's a thread I found which pretty much sums up what some of our players are experiencing, esp Long n Ama, hopefully Blizz will realise the validity of this thread and solve the problem with their ISP. It might even answer some of the connecting/logging in problems we are experiencing turn by turn atm too. Looks like its AT&T who may be the culprits. Have a look, maybe even bump the thread so that Blizz will take it seriously.
http://forums.worldofwarcraft.com/thread.html?topicId=16474150203&sid=1
http://forums.worldofwarcraft.com/thread.html?topicId=16474150203&sid=1