Minecraft will
get out of its beta status the same day that
Elder Scrolls V: Skyrim is released. Hence, Markus Persson is calling the release's tag line as "us too".
Now, the game won't probably be much different other than not having the beta tag line and if I am not mistaken, it
will get a price increase as well. So, if you're still on the fence on purchasing the game, you have a few more months to go.
The game will continue to get updates, of course and make you use up all your free time building things and killing monsters. Hence, I've used my will power to not download the game as I have very little free time as is. I think Jeremy did though and is in the current process of building Castle Greyskull.