Apple is now offering the videos from WWDC 2009 for sale for none-attendees.
I've had several people ask me if they should buy these videos or ask if they "are worth it".
I've held off responding to those inquiries so far, not to be rude, but because I wanted to make sure that I was careful about my recommendation. You see, I find this a difficult question to answer for someone else. If I hadn't gone to WWDC, I would buy them without hesitation. It's hours and hours of information ranging from beginner level to advanced, with a considerable amount of information about what's been newly added and what's coming in future releases.
Your situations may not be the same as mine. As a full-time writer and programmer working only with Apple technologies, it's really important that I stay on top of things. I need to be aware of what's available as well as what's coming down the pipeline. For many independent Mac and iPhone developers, those things are equally important so they can adjust their product roadmap appropriately. For me, and I would guess for many independent developers, the answer really would be "can you afford not to". As a business expense, $300 or $500 isn't very much.
For a casual developer, however, someone with one or two iPhone applications in the store, the equation becomes more a question of can you afford them. $300 per track, or $500 for both is very reasonable for the amount of information contained in the videos and slides, but whether it's worth it for you will depend on your own financial situation and whether you need or can use that information. I don't want to give a recommendation that causes anyone to spend money they don't have or can't afford.
Are the videos great? Yes, most of them are really great. Are they fairly priced? Yes. Should you buy them?
I'm going to have to leave that last one to you, sorry.