Microsoft isn't changing Minecraft. They just bought the rights. It's like buying a share from the stock market. You don't actually buy the company.
And, as Minecraft goes, it has passed it prime. It seems as though other PC games are starting to prevail. The community is shifting to a younger audience too.
Honestly, I think Mojang is going to wrong way as far as survival goes. They made survival boring and dull. It doesn't have the same difficulty and feel to it like it had a while ago.(I think hunger ruined it.)
I only think that the hunger system is flawed, not BAD.
If Mojang doesn't change something then the game will die.
The only thing keeping the game on it's feet is the servers. But now bukkit is gone, and there has not seemed to be innovation in minecraft since Wynncraft.
After a while, the only thing keeping the game on it's feet will be the modding community. There seems to be innovation there because it's not as accessable to everyone, which means you have to have some talent to make a mod.
Also, once a mod is made, it's made. It can't really be copied, and hasn't. Even when one has been copied(TMI) it seemed to be better than what it copied(NEI)!
So, I don't think minecraft will die as long as the modding community stays alive.