I think the main reason to go to a conference is to immerse yourself in a certain type if culture. I attended a query conference last weekend and I came out of it so motivated to work on new things. It is easy to get bogged down sometimes by the daily grind at work and these events feature speakers who can show you a different side of things - things that excite you. And the best part is that you are there with others that share your enthusiasm. It is sometimes infectious.

I would say that the type of person that attends a Google i/o conference appreciates the cutting edge in terms of mobile and web technologies.