As a primer for getting you ready for Windows 7 & start to build the reasons why you should upgrade, you are 4 cool things that Windows 7 does that Vista (and XP) does not:
1. XP Mode
This time, you do not have to slap your head that same way when Vista would not run an XP application. For those XP applications that do not work under Windows 7, you can download XP Mode free from the Microsoft website and run XP applications in an emulated XP environment in Windows 7. Imagine Parallels on Mac OS X without the need to fish out money on an extra OS.
2. Problem Steps Recorder
The 'Problem Steps Recorder' lets you record a particular problem you are having with your PC so you can send it to someone who may be able to help. Click 'Record', and a screenshot is taken with every mouse click, allowing comments to be added in between if required. These screenshots (and comments, if any) are placed in a well-formatted HTML document that is placed inside a zipped folder on your desktop - ideal to be attached to an email.
Jumplists are a new feature that give you the option to view a list of recently accessed files by application, even when the application isn't open, by right-clicking on the application's icon in the taskbar. It also allows you to quickly access a favourite playlist without opening your media player. Jumplists can also be found integrated into the Start Menu.
4. A Step Forward in Previewing
In Vista, hovering over a minimised window on the taskbar would provide a preview of the window. In Windows 7, a similar preview pops up which also gives the option to close a window (within the preview), along with a full-size 'peek'. You can also press Win + T to scroll along previews in the taskbar.
While any of these on their own isn't a reason for upgrading to Windows 7 for your new PC, it's starting to (finally) look like it's going to be time to get off of XP pretty soon & move into something actually developed within the last 8 years! :-)