Notch said he was leaving if that happened, right?
His official explanation for why he's leaving. I have to admit, it's pretty teary. This definitely sucks, but this would confirm the Microsoft-buyout is convenient, but not the cause. I wish him the best and I'm looking forward to seeing what stuff I can learn from him in the future.
It's very much the Swedish personality, though. A lot of them don't want to be big and want to be quiet and reserved.
The reason I don't understand the buy-out hate is become Microsoft isn't made completely of idiots. They are profit driven, and as it stands, there's significant profit to be made on all the alternate platforms. I believe that we won't be seeing the effects of the buy-out for a long time, so just enjoy Minecraft as you always have.