Who of Windows 7 a huge leap forward with design change and endless new features expected quasi a change of direction, which is probably more disappointed. Instead, Windows 7 is more of what had been promised in Longhorn: It's as fast as XP, support plus the latest DirectX and is compatible with most XP and Vista all applications - the compatibility mode makes it possible. For this purpose usually is not even the virtual XP, the Ultimate version needed; often instead satisfies the said mode, which can be set as in Windows XP and Vista in the properties of the file. Another advantage over XP: The 64bit version is actually a (as with Vista)!
Look and feel are the Vista very similar: Aero ensures transparent task bar window, again are gadgets here (but this time as a freely positionable widgets) ... Who does not like (or where the processing power is not enough), which may in the classic style cross over and turn off the gadgets.
Pretty is the periodically changing the background, but that's a matter of taste.
I welcome also that a few rudimentary graphics drivers are already included (and better than the older Windows Verisonen) - from so deleted immediately jerky presentation immediately after reinstalling the operating system.
Conclusion: Windows 7 is the best Windows currently on the market: faster than Vista and are fully compatible to more versatile and prettier than XP plus safer. Who's afraid that his old programs no longer run, engages in an emergency the most expensive version (Ultimate) and uses the "built-in" Windows XP or by using virtualization software (there's also free). An upgrade is worthwhile in any case.
PS: I am aware that Windows 7 is not yet on the shelves. But since I am a student, I is thanks MSDNAA Windows 7 since the beginning of September available, where it is the Professional 64bit version. So far, I am extremely pleased.