Many web video services are now serving HD 1280 x 720; we'll see how much it'll cost to stream millions more video from the cheap Christmas "flip" cameras at rates 7-10 times the original YT bandwidth. Facebook is also letting you embed on other sites now. YouTube hasn't acknowledged their HD (link/format "&fmt=22"), but they added a "watch in HD" link if the uploaded content was that size. Maybe they want to avoid Hollywood's reaction to seeing stuff in HD; see Big Buck Bunny.
Techvideoblog has a quick Online video sites HD quality comparison. He misses YouTube quality level "&fmt=06" mentioned here last month in YouTube gets HD & quality confusion, and there's tangerine in with the oranges, but I've never even visited referenced sites SmugMug or Sevenload.
Here’s an interview Robert Scoble did recently with Chris Putnam, a leader of Facebook’s video efforts, who discusses the move to a new codec and other aspects of the upgrade.