The demos by MixBook and SlideRocket were also really impressive. I was particularly blown away by SlideRocket. I was talking to one of the Adobe guys during a break and he told me that SlideRocket was completely coded by one guy, which just blew me away.
I was also really impressed with the Fireworks integration with Flex. I loved the idea of a designer using Fireworks to create a visual prototype using actual Flex UI components. Designer-developer workflow is still a holy grail of application programming IMO, and this was a small, but significant step in the right direction.
I did a presentation on using Flex to build a Facebook app. It was late at night. I was pretty tired and tried to keep it to 15 minutes, but I think it went over pretty well. I had lots of people asking me for the slides afterwards, so here are the slides in PDF. Also, here's the code for YouTubeFaves.