Blizzard has updated their real-money Auction House FAQ for Diablo III with more details and pricing fees for the new feature. One thing to note is that if you opt to use the feature to sell, you will be paying Blizzard a hefty chunk of the take. Several fees are included for item transactions that include the following:

For Equipment (weapons, armor, accessories, and other unique items)

• Transaction Fee (Gold Auction House): 15% of final sale price
  
• Transaction Fee (Real-Money Auction House): $1.00 USD per item / $1.00 AUD per item
  
• Transfer Fee (when sending proceeds to PayPal or other authorized payment-service provider): 15% of amount being transferred

For Commodities (gems, materials, dyes, pages, recipes, and other non-unique items)

• Transaction Fee (Gold Auction House): 15% of final sale price
  
• Transaction Fee (Real-Money Auction House): 15% of final sale price
  
• Transfer Fee (when sending proceeds to PayPal or other authorized payment-service provider): 15% of amount being transferred

Find out more about Diablo III's real-money Auction House via the official FAQ.

In addition, Blizzard has also revealed details about Diablo III's Global Play option, which will allow players to play the game in regions outside of their own with a few restrictions. Through the feature, players will create characters in their home region and can use the in-game menu to switch to other regions. Characters, items and friend lists do not transfer to other regions, so you'll be starting fresh. Find out more in Diablo III's Global Play FAQ.

Sources: Diablo III Global Play Announcement, Diablo III Auction House Update