Summary of Gtalk 1.3 issues: (for those who wonder if it's worth it).
- Video/Voice from other party is visual/audible.
- Video from your side is broken (other side just see your google account avatar)
- Theoretically to enable voice calls to your phone you need to click on your status and tick the allow video/voice calls.
- Initiating calls to your phone isn't possible (you can't call from a computer to your phone).
- Initiating call from nexus to nexus (or other phones which I assume aren't nexus s with official google rom) isn't possible. your phone or the other phone won't be shown as voice call available.
To sum it up,
It's a nice "preview" but far than being truly worth switching to at this state.
most video/audio functionality is broken for real use (unless you want it to call people with computers for talking with them and watching them... that's the only thing).
The good thing is it's not worse than the older gtalk so the standard gtalk functionality won't be worse