Well April Fools has started and Google has already started a few off already.
YouTube New Viewing Experience
Stupid and useless, but still funny.
? YouTube New Viewing Experience
Street View Panda
When on Google Street View, in the bottom right hand corner the yellow man is now a Panda.
? Google Maps
An Australian Football with a built-in GPS system that costs $10 (AUD)
? Google: gBall
I'll update this with anymore that they do when they're discovered.