THIS is very cool.
We used to have scheduled Videoblogging Group video chats back in the day. Watch me talk about those early video chats in my talk: Introduction to Videoblogging at Podcast Academy - May 2006.
People could just pop in and video chat.
The thing that I like about The Google+ project: Hangouts is that it's not planned, without a schedule, rundown, or agenda.
There are times for planning, like SteveGarfield.tv, tune in Thursdays at 2 ET :-), but I like the idea of this free form open chat room.
See also an interview with Grant Crowell and me: Video Chat Platforms – Choosing The One That’s Right for You at ReelSEO Video Marketing
Update 6/30:
Tried it.
It works, and you can watch YouTube videos together.