Oh, ok! Here, play with the latest version!
This is not official in any way, but I’ve gotten several requests that people who paid should be able to play the latest version, even if it’s horribly buggy and crashes all the time.
And I agree. They should be able to do that, at their own risk.
So here you go:
http://www.minecraft.net/indev/
Please, do NOT report bugs you find in that version! I KNOW there are bugs, and I KNOW there are a lot of them. It’s much easier when the only bug reports I get are from the official game releases.
The model in there is not what the final model in the game will look like. It’s just there to test the MD3 loading code so you can see that, and the player shadows.
