Diablo 3's 1.0.2c patch has gone live in America, with a global roll-out scheduled to follow imminently.
The headline feature is that the real-money auction house is now live. This, as the name implies, allows you to spend real money to buy and sell goods using an auction house.
The patch also changes the login system to remove Error 37, instead replacing it with an "authenticating credentials" screen. This, in theory, should remove some of the load on the servers from people hitting cancel and repeatedly attempting to login. Fingers crossed it doesn't just hang on the new authenticating credentials screen for hours.
The achievement bug has now also been fixed, and will award the correct achievements to players who have completed the unlocking criteria but did not get their points.
Blizzard has recently threatened to ban cheaters after an item-duplication bug was found.