It is true that Vista can do some fundamental things that other versions of Windows cannot (easily) - live thumbnails is a good example. HOWEVER, this is down to the poor way Windows is written rather than something special in Vista. For instance, if you hit Alt-Print-Scrn, an image of the foreground window is placed on the clipboard. You might reasonably think that the Window is redrawn into an off-screen bitmap, but in reality, all it does is copy that portion of the screen that the window occupies (in Vista, this leads to dark smudges in the corners - the shadow).
Many common controls, such as buttons and edit boxes don't follow the rules. They may process WM_EraseBkGnd messages and WM_Paint messages properly, but often they simply draw directly to the screen. This probably accounts for Vista's ability to do several things that XP cannot.