There has been a Lightroom 3 Beta available for a while now. I personally don't download beta programs, on the advice of my good friend Steve Dreyer. However I like to learn as much as I can about them so when they do get released I'm up to speed.
Matt Kloskowski on his blog, Lightroom Killer Tips, has a new video that you may want to take a look at. I really like his style of teaching.