Microsoft has always upped the ante on hardware requirements for it's new and improved OS. People are too ready to fallinto that upgrade trap and buy hardware and solftware solutions that probably only 10% max will ever use.
I can surf the net as well (read about as quickly) with my trusty PII-400 and a 10 gig drive and Windows 98 with a broadband connection as my newer machines. On a PIII and 256 RAM, Linux will be just as quick, and free, and much more secure.
If I gamed or did a lot of digital imaging that might be another matter, but I don't.