If you were looking for one more reason to upgrade from XP to Windows 7 TechRadar has 18 of them.
Some of the more interesting ones include the advanced preview mode found in the task bar. The new Jump List that allows you to see files that were recently opened by an application by right clicking on the icon in the taskbar. Problem step recorder, which allows you to do just that; record a screen shot of every step you take (every click). This handy little app even puts all the information into a Zipped HTML File ready to be mailed.
For me the biggest thing that Windows 7 has that Vista and XP did not is really and truly improved performance. Although there are no DX11 games the remake that went into DX11 and the additions are well worth the price.
The fact that we already have three games announced that have DX11 engines ready to go at launch is impressive. I think the total number of games ready for Vista (other than Microsoft Games) at the same time in its launch cycle was one. Even then they were combination DX9/DX10 games with very poor implementations of DX10.