I am a mod player, and this has me worried, especially since MS just dropped a good chunk of change, I highly doubt they bought it just to keep the status quo. And I have a bad feeling that the first ones to feel the impact of this decision will be the modding community. My hope, all though not expectation, is that MS will leave everything as is on older versions, and use what they bought to build Minecraft 2.0 and start whatever changes they wish to make from there. But, considering the fact that 1.8 is out and 1.64 is still the most popular to mod version, I don't see them considering leaving the older versions just out there doing their own thing. Blah, good for Notch, guy made out like a bandit and can program at his leisure. Just not happy with the what may be in store for us.
BTW, how does other MS games work their servers? Are they all run in house or do they allow people to set up severs not unlike a Minecraft one now?