If you're curious as to why IT tracks are gone, Mac tracks are limited, and Apple Design Awards are restricted to the iPhone and iPad for WWDC 2010, there are few people better equipped to answer you than Steve Jobs, CEO and Chief Customer Service Rep, of Apple Inc:
Is there any particular reason Apple has dropped the Design Awards for the Mac? Any plans to have them again in the future?
The Steve Jobs response:
We are focusing primarily (though not exclusively) on iPhone OS this year. Maybe next year we will focus primarily on the Mac. Just the normal cycle of things. No hidden meaning here.