A nifty little name changing tool has been released.
I got tired of playing sc2 offline as Local Player so I wrote a simple little program to run and change my name to whatever I wanted.
Right now you have to run this after the game has launched, but I’m sure it would be quite easy to set it up to loop until the game exists.
I wouldn’t suggest using it while connected to battle.net
Get it here: http://www.blizzardbeta.com/files/sc2name.zip