The System Profiler gives you more information about your Mac than you ever probably wanted to know, and manages to arrange it in a mostly user-friendly way too.

The selection of "widgets" on the Dashboard hasn't changed much, although worth noting is that most of them rely on internet-enabled nonsense and don't work anymore.

Not much really to say here, Spaces hasn't changed a whole lot since it was introduced.

The Finder also really hasn't changed, although I will use this opportunity to point out that the user interface did get some appearance tweaks: the depth is lower and the colours lighter on the window controls.