Minecraft 1.5 Beta should be released next week, my guess is 14th April based upon past relsease schedules. It looks like finally Minecraft will get statistics and achievements with this next relase, personally I am unsure of what the stats and achievements will bring to the multiplayer Minecraft experience which is basically the ultimate sandbox experience. However they may add a much needed source of direction for the single player experience.
Quote from Notch “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.”