Sure, Apple carved out a lot extra code, like printer drivers you don’t need. But you’re also seeing additional space where you didn’t used to, because Snow Leopard calculates disk capacity differently than Leopard (or Windows, for that matter).
Previously, storage was calculated using binary (base 2), which is why you wound up with hard drives that the manufacturer said were 250GB looking like they had 232GB of space in your OS. Snow Leopard calculates disk space in base 10, so your 250GB hard drive actually shows up as having 250GB of space. Check out that shot by Gina of the same 4GB Cruzer drive in Leopard, then in Snow Leopard to see what I mean: