As mentioned in another thread, I tried this two days ago. It worked (I sent the invitation from my N800, the other party got it through the chat, clicked the link, installed the software, rang me back). The video looked good, or rather, the video of me looked good for the other party.. he couldn't get the PC webcam to work with the software (it works fine with Skype). But we both heard severe voice breakup, and he also found that the PC software used some 98% CPU on his laptop.
So, all in all, it wasn't too useful because the voice wasn't good. We were on high speed good links, and whatever I did on the N800 (web browsing, internet radio, ssh, the works) didn't make any difference one way or the other, voice had exactly the same breakup all the time. At this stage I suspect the PC software part isn't quite up to it.