I was browsing the WoW forums real quick tonight before turning in (this contract thing has me up abominably early in the morning!) and noticed that the Public Test Realm forum is once again available (and has been wiped clean). In addition, copying a character from the live realms to a Public Test Realm appears to be operational, and you can download the PTR client as well. However, the PTR client is still an old build for the moment, and none of the Public Test Realms are actually up yet.
Still, being the PTR junkie that I am, I am very interested in all this activity! I just hope it’s all ready to go by the time my plane lands tomorrow night.