Actually, I could care less if the vendor supports the OS. As long as firewalls and anti-virus software stays up to date, I can put up with known problems. Heck, I still run Windows 2000 on one of my computers and see no need to upgrade. Only when other software outruns the operating system will upgrades be considered.
I just want a fast and reliable operating system as a single user. Of course business’s are different altogether...
I run W2K when I just need another offline copy of Windows for a while -- no license requirements. And I have a 10-yr old 800MHz Pentium-3 laptop with 256MB RAM that runs W2K perfectly well, and I use it from time to time to this day for light websurfing while exercising (it's strapped to the stationary bike).
But for serious online work I use Win7 or XP.