Notch's next game is an MMO
Technology of note: "The computer in the game is a fully functioning emulated 16 bit CPU that can be used to control your entire ship, or just to play games on while waiting for a large mining operation to finish.
[...]
The cost of the game is still undecided, but it's likely there will be a monthly fee for joining the Multiverse as we are going to emulate all computers and physics even when players aren't logged in."