Wow Vista

Vista's Aero visual environment includes the flip 3-D feature, which allows a user to cycle through a stack of open windows to find the desired application, shown above, and translucent window borders. Vista also offers "Gadgets," small programs that recall Mac "Widgets" (far right of screen above).

Yeah, quite interesting approach, but many users out there didn't like of its huge resource consumption which makes your (old) computer work slower and some may think the os had crashed.

As a conclusion, don't go for Vista yet, unless you are ready to loose few of your working program/software, probably i think we should wait for Vista SP1 to avoid any potential bug. And the software publisher also need sometime to make their software work with Vista.