http://www.pcgamer.com/2012/11/29/notch-mega-interview-0x10c-micropayments-kickstarter-and-quantum-computing/
"How will multiplayer work? Do you all have your own spaceships? Or are you encouraged to form crews together?
The idea is kind of to allow for both. It’s still not clear how we’re going to monetise the game – but the rough idea I have right now is to have an MMOish part called the multiverse. It’ll probably be monthly subscription because of the cost of running all the [spaceships’ emulated] CPUs on the server. The idea is that one subscription gives you one generator. If a CPU in the game costs us this much money to emulate then it has to consume an equal proportion of the wattage from the generator. So several people could play on one ship with one generator if they wanted. I think that’d be the most fun, but I know a lot of people just want to pilot their own ship. That part of the game kind of grew stronger after we played the Artemis Ship Simulator."