The Minecraft 1.3 update will be released August 1, 2012, developer Mojang has announced.
The highly anticipated update features a huge number of changes, as the development team explains.
"The most dramatic change is that we've kicked out single-player, and made it a shell on top of multi-player. There are two major benefits to this: first, it's required for the modding api if we don't want to have multiple implementations of every mod, and second, if we fix a bug in single-player, we know the bug is fixed in multi-player, too. Previously we had to fix bugs both in relation to single-player and multi-player."
There update list is so long that we're not going to post it here, but Mojang has kindly listed everything on its website, broken down into the good, the bad and the ugly.
One of the most obvious negatives of the update is the increased load on CPU, which won't be fixed until the 1.4 update.