Wiki link: http://en.wikipedia.org/wiki/Guy_Kawasaki
Technically he’s not a Googler as he is a Motorola advisor (to none other than the CEO). His Facebook announcement on March 1st linked from Wikipedia is curiously missing, but I did find a post on his timeline about the jump.
I learned about his blog years ago, though I had never used a Mac before I got a MacBook Pro on my first day at Google. I stopped reading in a short while as I couldn’t keep up, but I do remember his 10/20/30 rule for presentation.
Even though he left Apple almost a century ago, I think he was still known for the “Apple Evangelist”, so this seems like a nice coup. But he’s been championing Google stuff for a while, e.g. saying G+ is as special as Mac, so it could again be just my ignorance.