No, it isn't. iTunes is for music management. The iTunes Store is for purchasing media, as well as applications for Apple products. The built-in sync functionality is exclusively for Apple products, because those are the only ones they're required to support.
Any other manufacturer can create a plugin or a sync utility for iTunes, using documented APIs made available by Apple. They just have to assume responsibility for developing, updating, and supporting that utility themselves instead of trying to pass the buck to another company. iTunes will work just fine with Blackberries, Windows Mobile devices, and dozens of other third-party devices if you go about writing a sync utility in an official, legitimate way.
I'm glad you pointed this out. Sometimes in brevity when posting, we tend to gloss over some details and simply use the generic 'iTunes' (or other product under discussion) term to refer to everything we're talking about. Of course it's never quite that simple.
Palm could have made their own sync app, and their customers could have still used iTunes to manage their music...
Another poster commented, essentially, that Apple would look like the 'good guy' if they let other products work with iTunes. In reality, they kind of do, at least with music since Apple convinced the labels to go DRM free. Other products will work fine with the music you buy in iTunes - it's just up to the 3rd party company to write their own sync app - if not, you could always manually import you music files into the other product. What Palm tried to do was hitch a free ride... and as an impostor.
I like the fly swatter picture post... that sums it up perfectly.
Now here's to hoping the MPAA will get a clue and drop DRM for movies, etc. You'd think they'd know by now that every film has already been (or will be) pirated, and any of us could get a free copy if we wanted to... Most of us however, just want to buy a legit copy and use it on any of our devices without hassle. DRM free video would further open up iTunes to 3rd party devices, but again, it would and should be up to the 3rd party to write their own sync.
The app store (subset of iTunes) is a different animal. That is, and was specifically created to service the iPhone/Touch. I don't see that ever changing or "opening up" so to speak, if for no other reason than the apps will only run on Apple products anyway...
Don't get me going - I could write a novel on each and every little intricate detail, and I don't have time for that... maybe one of the reasons I, and most folks I would say, tend to keep it 'generic' when posting on forums.