”Microsoft has clearly announced to the public that it has designed the Xbox 360 from the ground up to thwart those who want to crack open the case -- even simply for a look inside. They have stated that the unit will be screwless (partially true) and be extremely difficult to disassemble -- unfortunately only partially true.”
They photograph each step, and it's interesting to take a peek inside. Of course, for being a $399 machine, it still does seem to me a PC, cramped into an even smaller space, though how far the level of integration we saw the Xbox go will compare to the 360 remains yet to be seen. There is still some room in the chassis, so we'll probably see a lot of modding come out of this. If you are interesting in hacking stuff up take a look.