I assume you're referring to the 30% of Windows users (XP) that will be left unsupported and unprotected in April of this year?
Windows XP release date: October 25, 2001
Mac hardware from 2009 is still very capable for what most people use it for: office suite, email and web browser.
(I could argue a optimized Windows XP computer from that era could still do well with today's software, but if someone is still using Windows XP on 10 year old hardware, it's probably running subpar)
I guess you would compare OSX version with service packs though, but I don't think that's fair.
Honestly Apple is playing the obsolescence card much more aggressively than microsoft, because they can. I installed Mavericks on my 2GB RAM macbook pro, and my laptop is already obsolete, it's very sluggish. I would GLADLY trade mavericks for windows XP. And I'm sure Windows 7 runs very well with that amount of ram.