Keep in mind you don't have to use/display CoverFlow. It's only there if you want it. iTunes though is very different than WMP (which is my least favorite of the majors). iTunes looks the same on both platforms, though much more extensible on OS X. Run through Doug's Applescripts
for one example. I use SlimServer/SqueezeCenter as much as iTunes, but I think the latter is an excellent organizer especially on the Mac (tag manipulation on that platform eliminates most file tree advantages and keeps all the DB ones).