Firingsquad reports three snippets about Diablo III that were previously unknown. First up, the game will require you to be connected to Battle.net at all times to prevent piracy and cheating. Next there won't be support for modding the game, and the third revelation is that an in-game auction house will allow players to buy and sell items using real-world currencies.
The game requires you be logged-in to Battle.net at all times, even when you play single-player, and will drop you if you get disconnected. Blizzard insists this is to prevent cheating, but they've also admitted stopping piracy is another reason.
Modding the game will not be supported. Not only that, but Diablo III's terms of service will "expressly prohibit" them. This is for "a variety of gameplay and security reasons," but it's pretty easy to connect the dots: this, like the online-only requirement, are to help safeguard the third and final hot topic...
An in-game auction house will allow for players to buy and sell items using real-world currency. Blizzard's reasoning here is that they wanted to legitimize the cash trades for gold, items, and characters that cropped up around previous Diablo games, making it safe and easy for everyone to partake. They will be taking a cut for themselves, of course, both when an item is listed (to prevent flooding of unwanted junk) and when the transaction is completed. For those that want nothing to do with this, there will still be another auction house that uses only in-game gold.