OSX has a bigger memory footprint than Vista, and much more than XP, if i remember correctly OSX was using about 1.5GB in swap, i'm not certain so dont hold me to it, but it was large enough to raise both eyebrows, yet OSx was running relatively smooth.
And Vista, larga swap file and all, does run smooth on 512 so i would say - Yes Microsoft does know how to use a swap file, i for one use vista everyday since may 22nd, and it hasnt crashed at all, and i havent turned it off except to restart when i was installing a driver.....and its a beta!
when i get home i'll restart and see what Vista uses in memory on boot up