I've noticed it. Maybe they will make some other graphical changes too. Going for a more modern look maybe.
Ah i didn't notice that, you're right! It makes me feel like they are trying, with the new favicon, to look closer to us. The large "G" looked like a big corporation favicon and the smaller one makes me feel like an independant part of google that is closer to us and trying to work with us. You might say that i am going a bit too far with this (and you're probably right lol), but there is a reason why they made this change.
Constant changes is really great. Especially if its improving, i think it can give out a great impression even just simple icons.
I see new on in adsense and the old one in google search, and I think the old one is better since it is easier to see it on FF.