GMail numbers weren't broken out, but YouTube rivals Facebook at ~150m uniques monthly.
There's been a lot made of FB (and other social networks) primarily being photo-sharing networks. While I doubt video will ever quite have the same impact (they're deeper but not as casually shared), it probably will grow as a social element, and Google are beautifully positioned in this regard.
It's a growing trend, not necessarily new. Phones have video recorders, and quality and proliferation are growing. Again, YouTube's in the pole position, this is its race to lose.
Technology, even once widely available, can take a while to take off.
There's been a lot made of FB (and other social networks) primarily being photo-sharing networks. While I doubt video will ever quite have the same impact (they're deeper but not as casually shared), it probably will grow as a social element, and Google are beautifully positioned in this regard.