Other caveats.

1) SMS is not 100%, just like the GTalk SMS things like short codes are not supported, so you can't do things with services like Facebook/Twitter ( yet )

2) US only, international people are really screwed at this point since some will get the upgrade notice only to be unable to login to the new service because of their location. You have to use a US proxy just to be able to properly finish setting up the account.

3) Ringshare is gone

4) All your settings are wiped back to the default ( greetings, groups, ... )

5) All your phones are active after the cutover no matter what was selected before.

Almost-but-not-quite

Call presention ( "press 1" ) can be disabled on a global/group/contact basis... but NOT BY PHONE! This is dumb.