I heard on Podcast Beyond that Sony doesn't expect to sell the PS4 at a loss because the hardware being used isn't prepriotary. So if they got a good deal on those hardware relationships the price could be relatively low. If not...oh boy.
I would seriously be surprised if Sony could even come close to breaking even on this thing at launch. They are going for premium parts, more so than MS and both manufacturers have peripheral camera shit alongside the console. The potential for making money on the tech later in the generation will be huge though because the costs of making what are essentially PC's will drop a whole lot faster than with custom hardware. It's why the PS3 and 360 are still at the same price point for the longest time.