Minecraft is a bit of a phenomenon the mining and building game where all you use are perfectly cubic block with different properties. It has taken off in popularity with the relatively recent addition of multiplayer. The game is going to be officially entering the Beta phase where the creator, Notch, promises he wil get modding officially supported and continue to add content to the game.
There are two major changes that will be happening when the game enters Beta on December 20th the price will go up to 15 dollars and he is taking our a small clause from the original agreement for anyone who buys the game after the 20th. If you bought the game before Beta you will still get all version of the game including any expansions after the official release for free, but if you waited you will only get up to the offical release for free. This small change isn’t that big of a deal, however if you want to get the expansion free get over there and buy it at the 10 bucks it cost right now.