So there are a bunch of rumors that there is a live video. So far every link that is available has been false.

Live Stream – commentating only I believe
http://www.ustream.tv/channel/applelivekeynotes/v3

Here is where you can track coverage of the event through live blogging

TechCrunch – http://techcrunch.com/2010/06/07/apple-2010-wwdc-keynote
LiveTechEvents – http://livetechevents.com/
TheAppleBlog – http://live.theappleblog.com/
Gizmodo – http://live.gizmodo.com/
Engadget – http://www.engadget.com/2010/06/07/steve-jobs-live-from-wwdc-2010
MacLife – http://www.maclife.com/article/news/live_blog_wwdc_2010_keynote
MacRumorsLive – http://www.macrumorslive.com/
SlashGear - http://live.slashgear.com/
MacObserver – http://liveblog.macobserver.com/
CrunchGear – http://www.livestream.com/crunchgear