I think it is a dick move personally. I got an preorder in with Amazon and I confirmed my pre-registered interest as a pre-order with ShopTo but if I do happen to get two on release day, one will be getting sold to someone who wants it, at RRP. The thought of flogging a second one on for profit just wouldn't enter my head.
But plenty of other people will do it, it happens every time with every console launch and there's nothing that can be done about it. At the end of the day, people are trying their luck by putting them up for sale for inflated prices and there always seems to be people willing to be taken advantage of.