Looks like Firefox 3.5's support for open video has already inspired:
- Dailymotion to add Ogg support,
- The Pirate Bay to create a new site, The Video Bay, which features Ogg-only video, and
- Wikimedia to accelerate the addition of videos to Wikipedia articles. (Articles that already have videos include Geyser and Flywheel.)
And Firefox 3.5 hasn't even been released yet. This Open Video thing might just work.