I talked to someone there yesterday about it. He said their online ordering won't always say "backordered" when it's not in stock. I told him that was odd since I did notice several items that specifically said "backordered" status..

His response was that for some popular merchandise they don't list it as backordered because they can't keep them in stock, and (get this) "People know that those items are going to be backordered without us stating it".

I cancelled my order with them at that point. They called me back about an hour later and said they made a mistake, mine was on the dock waiting to ship out, and I have a tracking number. Not sure if that was an honest mistake or they decided to find me one since I wanted to cancel, but I did find something interesting last night. Someone posted on the Traxxas forums that their Slash order from RC Planet was placed by phone on Friday, and he was told it was in stock. He received an email last night saying it was backordered, and when he called he was told someone placed an online order a few minutes before he called and they didn't know it was sold. Sorry to that guy if I got his order, but it does look like I will have a Slash on Thursday.
I will still avoid them in the future because of their rediculous policy on not listing out of stock items as backordered.