Just a note for you running WoW on the older Macs out there-- PowerPC Macs were the last to run WoW's built in voice chat system on the PTR, and as of build 7125 (the latest, I believe), voice chat now works.
If you're running one of those fancy shmancy new MacBook Pros with the Intel processors, you don't care, and if you're running WoW in Windows, well I'm sorry (did I mention that I'm also writing for our blogosphere cousin TUAW now?). But for those of you running PowerPC Macs, feel free to load up the PTR and do some voice chatting.
Was the headline too confusing? "Public Test Realm Voice-over-Internet-Protocol on PowerPC is good to go."