well, i my p4 2.6@3.25 wasn not completely stable with my antec 350w trupower.. but no issues whatsoever w/ my 480w. again, it depends on the peripherals.
mine runs 2 optical drives
4 hard drivers
water pump, fans, and all associated with that
cathode tubes
sb audigy
ati tv wonder
and of course multiple items which run off usb power....
worked fine w/ my 9600pro, however 9700pro, 9800pro, 5900nu, all had issues until i upgraded the ps. would be hard to convince me this setup would be fine on a 200w ps as my 350w antec was working it's ass off tyring to keep up with all that