I'm a little late to the discussion, but...
At my job, we have laptops running XP and, get ready, Win2k so that we can program older PLCs. Newer is not necessarily better, and throwing companies with legacy equipment under the bus to promote shiny new operating systems to the public does not make for a very good business model. (Also, care to guess how much an Allen-Bradley software license costs per PC?)
While it is arguably showing its age, Win XP is still servicable for basic computing and light gaming. You can also mitigate the security flaws by using a browser other than IE (e.g. Firefox, Opera, Chrome, etc.), installing a good AV/Firewall suite such as Avast or AVG, using a well-engineered hosts file to head off dodgy websites at the pass, and having a modicum of common sense (not downloading from "w4r3z" sites, avoiding clicking on suspicious links, doing research before installing "free" games or utilities, and so on).
Incidentally, I build my own systems and got a lot of mileage out of 98SE and XP before the inevitable hardware limitations forced me to go with Win7 64-bit. Sorry Linux fans, but I don't have the time or patience to perform voodoo with WINE in order to play my computer games. I have enough of a challenge tweaking DOSBox for some of my older stuff.
