Apparently during a press only blizzcon "Real Money Auction House" panel, the press got (among other things) a exclusive written FAQ.
View the whole thing here
Sunshine edit: Official Battle.net link with the same questions/answers in a nicer format: http://us.battle.net/d3/en/services/auction-house/
It appears to be only a compilation of stuff said previously, or other stuff you can find online. However it contains 2 very intresting questions/answers.
And;If my character dies in Hardcore mode, will I lose the items that I purchased in the "Hardcore-only" gold-based auction house for that character?
Yes. Again, Hardcore-mode characters will only have access to a "Hardcore-only" gold-based auction house, not the currency-based auction house, and will not be able to trade with non-Hardcore characters. Hardcore is an optional mode designed for players who enjoy playing with the risk of permanently losing their character if the character dies, and that includes the items they acquired with that character.
Thoughts?What items can be traded in Diablo III?
Nearly everything that drops on the ground, including gold, can be traded with other players directly or through the auction house system. Aside from certain quest items, there will be very few (if any) items that will be “soulbound” to your character and therefore untradable. We are also planning to allow players to buy and sell characters in the auction house at some point in the future and will have more details to share on that at a later date.