Apple is intentionally keeping iTunes on Windows a "sub-par" experience to attract more users to move over to MacOS. I think the majority of non-power don't understand the problem is with iTunes specifically, and would say something like "The whole damn computer sucks".
</conspiracy>
Having never been an Mac OS user, I had always assumed they put all their effort into the Mac version, and then did some kind of nasty port and hacked away until a windows version worked. Not a conspiracy theory, so much as a lack of interest from Apple to make a decent windows version.
On windows, I use winamp. It supports my iPod, and actually allows me to listen to and manage my music collection.
Edit: It's been a while since I followed Amarok developments, turns out it's now available multi platform... Starts download on all machines...
I actually think I've heard this one before, especially when the software was just being released on Windows...