I have now been to every Google I/O, and I will say that this last year was exceptionally disappointing (by which I mean that I feel like it fell off a cliff as opposed to continuing a gradual decline). It used to be that you could go to the "office hours" areas, which were setup like rooms full of the developers that work on various projects, and kind of "hang out" with developers, talking about use cases and issues you had run into.

Last year, these were replaced with "help desks", and while the people there were very friendly (and while I really appreciated the one guy who went pretty far out of his way to obtain a stock image for a Nexus 7 when it seemed like I might have needed to flash one), all of the people identified themselves as "developer relations", not "developers", and none of the people I had gotten to know as key members of their team from previous I/O events were present.

(I also, like others, find the situation of "it is economically incorrect to not attempt to go to I/O due to handouts" ludicrous, and I wish they would stop doing it, even though I know it would make some of my friends who often attend with me sad. Google has tried to improve the situation by having handouts be given as part of talks and having the timing of central ones staggarred across the days, but it doesn't solve the core problem that there is no entrance cost to attending this conference.)