Jens Bergensten has just released this week’s working Minecraft snapshot after some issues occurred with the first attempt.
Bergensten had originally released 12w30a hoping that it would fix a number of bugs however it added its own practically disabling the right click feature. Thankfully this was soon noticed and Mojang have released an updated snapshot 12w30b. One of the known tweaks is that creepers no do less damage on the easy difficulty and more damage on hard mode.
If you wish to download the snapshot, head over to the Mojang website.