The 360 is moving to a 65nm process early next year (January), which will really reduce the cost of 360 even further (more chips per wafer). I fully expect a price drop by no later than May 2007.
Also, those costs don't include the cost of shipping, packaging, cables and manuals included in the box, etc. I would guess the 360 after all costs makes a tiny, tiny profit, or a very small loss.
The PS3's loss per console is even greater than that chart shows after you include the same additional costs. I doubt we see a PS3 price drop for at least 2 years. The technology is just too prohibitively expensive for Sony to have much price flexibility anytime soon.