Yes, the nforce can have its FSB overclocked. The nice part about it is that the PCI clock will stay locked at 33mhz no matter what FSB setting you adopt. Most BIOS'es have the option to FSB overclock built in.
Having said that I'm not an overclocker so I don't know what sort of results you are likely to acheive. I would point out however, that it probably won't be the chipset or your memory that ends up limiting you, but rather the cpu. The EV6 architecture can't easily/reliably go above 133mhz DDR without revision (one of the reasons why AMD has not yet introduced an Athlon with a 166 mhz DDR FSB) so your results will vary from chip to chip.
Greg