I was following this as soon as I heard the news, and I was actually a bit upset to hear it was true. Now, Bungie was purchased by Microsoft in days of yore, and it seemed the development of the Halo games was largely untouched after the initial development of the game (from a Mac RTS to a Xbox FPS). So long as Mojang developers like Dinnerbone and Jeb remain, the game should be fine, but as soon as they leave if ever, the game could get pretty ugly.
I'm mostly upset because this was the first game where I felt my voice actually mattered. Maybe it was because I was growing up (purchased this in Fall 2010 during high school), or maybe it was because the interaction between the consumers and Notch, Jeb, and Co. on Twitter actually influenced future, content-adding updates. Seeing it grow from this little Java game to being merchandised in my local Target was mind-blowing enough. My biggest fear is the loss of community-to-developer relationship. Notch was just another gamer like everyone else here, he just could make games too.
Seriously Microsoft, what are you thinking? you could have funded 8300 desperate indies with 300k each and gotten some huge hits out of it...