Practically all the PCs currently on sale at PCWorld and TheComputerStore that are mid-range or higher all have a gig of ram and a 3.0Ghz CPU anyway. In a years time they'll all have 2 gigs of ram.
When the first Doom3 alphas were leaked/released, people were shocked at the steep requirements, but months past and newer hardware came out to accomodate this.
One good thing about Longhorn is that the lower-end and no-name periphial and component mfgs are going to go out of business (woo! no more BSODs)