But where's the damn mod API?!
There's not going to be a modding API, Notch said that he wouldn't be able to make one comprehensive enough to work with all mods as well as not breaking with each update. Instead, he plans to create some sort of official modding partnership thing that will give modders complete access to the source code and comments, as well access to code for upcoming updates. Some people tried to lynch him over it yesterday.
The map thing looks cool, but I feel that it kinda missed the boat a bit. There's so many mapping tools available now that there's no novelty to it. Not that I don't appreciate adding an official one into the game, that would have come in very handy during my first few weeks in the game. And I'm sure it will be useful whenever I head out exploring again.