[derefr]

Indeed, it did start out as a part of OS9. However, I think the Principle of Charity applies here—Apple generally employs good engineers, and they got everything else native-ized, standardized, POSIXized, etc. for 10.0. There must have been a particular reason for iTunes being the one thing that got left out of HIG-ification in 10.0 and every update since, and I propose that that particular reason is Windows support.

Yes, Windows does have hooks to add functionality—but hooks aren't enough. The reason Apple could remove components from iTunes was that it could, itself, integrate them into all shipping copies of OSX. Apple doesn't decide what drivers and plug-ins get shipped with Windows, so anything they'd install would be third-party and after-the-fact (which is what already happens: e.g. the CD burner driver bundled into the Windows iTunes installer.) You can't slim down Windows iTunes because you have to ship all the programs that make up the functionality of iTunes, whether modularly or monolithically. However, you can slim down OSX iTunes if you just start saying "this will be an OS feature, not an iTunes feature."

Also, on a completely unrelated note:

> The phone almost gets it right except for the gratuitous password nag.

I've always taken that to be a sudo escalation prompt. You don't want your kids picking up your phone and buying things on it.