If you're a fan of Blizzard's cinematics and trailers, but don't really want to download to watch them, you have an alternative. Blizzard today announced the opening of their official YouTube page. Check out the announcement below, or head to http://www.youtube.com/blizzard to begin watching!
Quote from: Bornakk (Source)
The new official Blizzard Entertainment channel on YouTube is now live! http://www.youtube.com/blizzard
Check out high-quality streaming versions of our cinematics, gameplay trailers, and in-game movies. Make sure to come back often, as we will be adding even more video content in the weeks ahead.