Details of Mojang AB's new game have been released.

http://notch.tumblr.com/
Read "Ah, I forgot."
Seems pretty meh, but it also seems quite interesting.

You linked to his blog, not the actual news post

I suspect that you are referring to Scrolls. Interesting, I say. I will be happy to purchase the game if it pulls off well. The only thing that worries me are micro-transactions, as in paying to unlock cards.