I haven't really looked into this, but I would think the problem is more technological. Deaf are very spread out and in some parts of the country/world you don't get the same video feed or the servers are older, not the same speed for everyone. As far as chat rooms, I would imagine there are a lot of them as they have been around for years.
Group video through phone might be possible, but you would have to use an Ipad type device as your phone would be too small. A major provider like Sorenson could do this, but everyone would need cable internet, I think.
Socially, there are places where a lot of deaf hang out like Allston/Brighton bars in Boston. I'm sure other cities have major hangouts.
