Microsoft clear 'won' the OS wars, but Google and Co have decided to move the goalposts by promoting web and cloud based services. Through the use of virtual machines and API translators like WINE, you can also run non-native applications, so I'm starting to see people move away from Windows. For the 90% of the population that uses only a web browser, email client and office package, your choice is wide open.

My own solution to writing platform independent application software is Java.

I'm going to retire my trusty XP machine (not least because XP has always behaved a bit oddly on this installation), and I'll probably go dual boot Win7 and Ubuntu Linux. £109 for Win7 Professional OEM might seem a touch expensive, but it's lost in the noise as soon as you lose time through not having it.