XP has looked like shit for years already but people still cling to it like a tree in a hurricane.

Ten years is way too far in the future to place any bets.

As one data point I was always the next upgrade until about 2006 or so when budget PC's hit a point that they would do everything I wanted as fast as I wanted. I mainly use a mac now, but my PC is probably 5 years+ old and does everything as fast as I would need.

Not upgrading is an option if there aren't really critical issues. "looking great" is not one of them - only being compatible with multiple must-have applications would do it.

WinXP + IE6 is still an option and it has been 10+ years already. If windows 8-9-10 sucks, then win7 can easily carry on for as long as hardware manufacturers keep shipping compatible drivers; and if windows 8-9-10 sucks, then they can easily do it for dozens of years.