This seems like a really nice idea. I think people use facebook and twitter and other vaguely similar social networking sites, so that they have an awareness of what their friends are up to. Pervasive tab-keeping as it were. I know that I may not have an actual vocal conversation with my friends for ages and ages because I live in a completely different town to… well, all of them actually, but I know for the most part, what they are all up to thanks to blogs and facebook.
This, on the other hand, I think would be really great for people who aren’t familiar with all this new-fangled technology, much like the Wii is great for people who aren’t “gamers” but want to give it a go and have a bit of fun. It’s more accessible.
I can imagine grandparents or young children really getting something out of this, because it could just sit on a nearby table and keep them in touch with their families who might be elsewhere – like at work.