Minecraft currently has currently sold about 2 million copies of it’s game and it’s still only in beta. However, the developers have just announced that the game will officially launch on 11/11/11. Minecraft is already selling about 10,000 copies each day and I would expect they will continue to do so after the official launch. The date 11/11/11 was actually chosen because it falls on the same date as other various game releases, the most notable being Skyrim.
The dev team has also said that there won’t be much difference between the beta version and the release version right after launch. The biggest change will be the removal of the beta logo that you currently see when playing. They have however details some changes that will be coming in the next update:
We’ve been working on finishing up Achievements and Statistics for 1.5, I ran into some issues with JSON, got frustrated, and added weather instead. Developing new features like that is what I enjoy doing the most, so I ended up covering a lot of ground. There’s periodic downfall (snow in snowy areas, rain in others, nothing in deserts) that make the sky darker, hides the sun, moon and stars, and makes everything wet. Ice grows back in cold regions, and snowfall covers the ground when it’s snowing. During rain/snow, there can be occasional thunderstorms with lightning. I haven’t finished the actual lightning bolt yet, but everything else is fairly done.
Once the stats are done and the weather has been tested through, we’ll release 1.5. I’m guessing this will be next week. The piston mod might get added, but it will not be in time for 1.5.