I like the idea of the RMAH and will use it to get a cheap upgrade from time to time. However, lately, I keep running into that "Auction is currently under review." much more often than ever before. Right now I am waiting on a review for a $3.00 glove. This is day two of the review. The money has been in my Blizzard account for over a month and this is not my first purchase using that money.
I wonder if this is an attempt to discourage use of the RMAH, or just much more vigilance due to so much duping? I have a hard time understanding why it takes 2 days (and it's not mine yet) to review something so simple.
I use it approximately once a week or once every two weeks and I rarely have this problem. It usually takes about 1-3 hours at most for me. Sales take longer (once it took over 24 hours to get my $150 for selling an IK chest), but usually they're done within a day.
It took a day once for me when purchasing a ring. I am not sure why but it was something that had only happened once. Every other time it has taken just an hour or two to process. The longest wait seems to be when selling gold or big ticket items.