does google talk video work? I mean desktop google talk.
No. The Google version of Google Talk has no built in support for VTC (video teleconference or video chat if you will). Interestingly, this isn't a limitation of the Google Talk infrastructure, as you CAN do VTC over Google Talk using two Macs running iChat. The protocol in use and the servers WILL do video chat.
I have recently been testing a new N800 on one end and iChat logged into a Google talk account on the other. Text works fine, voice and video do not. I'm going to keep picking things apart and see if I can't figure out where the point of failure is.