Yeah, I remember when a new version of Android came out that was 4x faster and I felt like I was the only one who interpreted that to mean that most of the CPU cycles were completely wasted by the previous versions. The same thing applies to OS X, where every version has been faster on the same hardware.

People talk about software performance, but another way to look at things is that hardware provides performance and software (especially OS/middleware) only provides overhead. So software doesn't really get faster, just less wasteful.