Just because you CAN doesn't mean that you HAVE to.
I don't feel like booting up Windows at home, but I did install it on my PC at work, and I have to say that I was rather impressed. It felt like Winamp 2, which is a very good thing. I thought I would be using Winamp 2.91 until the day I died, as Winamp 3 sucked so bad. Winamp 5 truly isn't that bad, although I just can't see the justification in upgrading if you already have Winamp 2.91.