A couple things..
1) That screen shot is definitely from Mac OS X 10.1. You don't even need to rely on subtle differences in the Apple logo for the Apple menu. How about looking at the OTHER side of the menu bar (HINT: SYSTEM MENUS).
2) That's a pretty damned convincing "fake" if you ask me. But I think it's real. All those things that you mentioned are probably problems with the UI. Also, I believe that with TinkerTool you can change the size of the System Font (maybe I'm wrong). But again, JPEGs degrade images, so that might be the problem.
3) Stop complaining about not being able to theme the GUI when you actually can. It's called MetaMorph X. Although it does have some serious bugs, and you shouldn't use any themes that are not compatible with OS X 10.1, it is definitely possible. It's not like themes in OS 9 were ever used that much -- Kaliedoscope was much more possible. To whoever complains about not being able to theme: a) Use MetaMorph X. If you hate that, then b) shut up and program your own theming application, because it's clearly possible. I really am getting annoyed by people who say there's a "monopoly" by Aqua. Plus, I don't see how three freaking little window widgets can make your pictures look so much worse. It's just like people who are lamenting over the fact that they can't get 590 fps like their friend can, when they can only get 540 fps.