i.e., the few thousand tickets available could have theoretically been sold out in seconds. The Moscone Center West would not even have the capacity for 25K+ Google employees, let alone the 10's of thousands of developers/students who would like to attend. My only point here is that there's a lot of demand and very little supply, so there's going to be a lot of disappointed people. I don't think a better registration system, programming challenges, doubling capacity, a lottery, etc will do much to placate everyone who wants a ticket. Perhaps the only sensible way to reduce demand would to be double, triple, or quadruple the price.
FWIW, I've been in 2009 and 2011 - in my experience, it's mostly engineers, developers and others interested in and actively working on Google technology - not people there for just for the freebies (although they are certainly welcomed).