When I bought my license it came with a promise that the game would be made open source in the future. That never happened.
> Once sales start dying and a minimum time has passed, I will release the game source code as some kind of open source. I'm not very happy with the draconian nature of (L)GPL, nor do I believe the other licenses have much merit other than to boost the egos of the original authors, so I might just possibly release it all as public domain.
This did not happen yet, Minecraft is still selling really well.
I'm disheartened also by the fact it'll never become open source, but the statement was never legally-binding and never part of the terms that a purchase of Minecraft (in alpha, at that) entailed.