As of Thursday morning the Player Test Realms (PTRs) have been taken down. Patch 2.2, which includes voice chat among many other things, has been a long time coming and will be released "soon".
Patch will be "soon" and probably sooner than most soons you've known.
Depending on how you interpret that statement, the patch could even be here before Tuesday, so be sure to fire up those background downloaders for a much needed head start.
http://forums.worldofwarcraft.com/threa ... &pageNo=23