They need to fix the AH before they even consider bringing the RMAH online. My main complaint, and I have been using this to make money for myself.
You can buy an item, send to stash and immediately resell the item again. This must be stopped. Basically, you search for specific gear you know will sell, set a low buyout like 5000 gold and just refresh and refresh and refresh. You see an item pop, you try and buy it immediately. You can then go and sell it for 10 to 20 times what you paid for it. Been doing this for days and making unlimited money because people are selling things because they do not know what to put for a value.
They need to put like a 2day cool down or something on items before they can be re-listed after they have been purchased from the AH to prevent people from controlling the AH like it is now.
Like I said, I am using this myself because it exists but it needs to be addressed before the RMAH comes online.
Also, they need to add a function so I can cancel my auctions that are not selling...so frustrating.