That would be hysterical (and sad) if the PS4 cost less at launch. I expect around the same price or maybe $50 more for the PS4 if anything, but it would be nuts if it was the opposite and would back up a lot of people who complained about being forced to buy a Kinect. You kind of expect the more beefy console to cost more but nothing is certain, especially when one of the companies is coming off of a pricing disaster last-gen and are trying not to repeat it in any way while fixing a lot of the other problems people had with them.
I kind of expect multiple SKU's from $349.99 to $499.99 but that's the most I could possibly see. I think MS really needs to launch cheaper than Sony though.
Obviously, this is just Pachter speculating so nothing too serious at the moment, but I fear that would be a huge mistake on MS's part.