Despite resisting the temptation to come on stage chanting "developers, developers, developers!" I think the entire Facebook Developer Garage - Palo Alto was great success. Application developers from (in my opinion) well over half of the popular applications on Facebook and a lot of independent application developers showed up and in general good times were had by all.
As far as my presentation went, I was apparently "a great speaker, spoke in depth about building apps thats scale." But in general the feedback was very good, and I spent most of the rest of the day talking to individual developers about short-term and then longer term growth and how to attack that from a developer's perspective.
Since I've updated the presentation, it's posted here again.