6. DirectX 10
If you want to get the most out of your GeForce 8800 or Radeon X2900 by playing DirectX 10 games such as Unreal Tournament 2007 and Crysis then you're going to need Windows Vista because, apparently, DirectX 10 isn't compatible with Windows XP. Or it's too much work to port it across. Or something.
Realistically, the developers of top-line games aren't going to ignore the massive installed base of XP users but if you want to get the full effects, it's time for a new operating system. No way is this blackmail on Microsoft's part, it's a technical issue. Honest.
7. Click... and it's there
The WinFS relational database file system may have famously been ditched during the development of Windows Vista but in its place is a search facility that works much like Google Desktop - and oh so fast. Vista indexes the contents of your PC continuously. When you run a search on indexed content - and the parameters can be tightly specified - the results come back almost instantly.
8. Windows Firewall: looking outward, looking inward
The firewall in XP monitored incoming traffic for nasties but we all know that's only half the battle. You also need to monitor outward bound traffic to make sure that any software that's reporting back to servers on the internet has your approval to do so. Updaters and the like are fine but Trojans and keyloggers are very bad news and need to be nipped in the bud. Vista's new firewall in Vista does just that. Bye-bye, Zone Alarm.
9. SideShow laptops and exotic motherboards
OK, so it's not so much a reason to upgrade to Vista as to completely update your hardware, but Microsoft's new OS for once has a good reason to do so, and not just the usual raised memory and hard drive capacity requirements. Vista adds support for a secondary screen called SideShow so you can check your email or look up an address without turning on your laptop or PC. Realistically, this is an acknowledgement that every version of Windows takes an age to load up so Microsoft has cheated by adding an embedded OS that syncs with Vista to keep your data files all shipshape and Bristol fashion.
10. It's inevitable
Windows XP will be slowly strangled so you might as well get with the mission. Over time, Microsoft kills off support for old versions of the OS, and XP will prove no exception. And no doubt MS will also add killer features that are only available for Vista. You can expect this push to start with Service Packe 1, due later this year, and during 2008 and 2009 Windows XP will look as limp as a boiled lettuce until you finally give in to the pressure and buy a new Vista PC or laptop.