I hate to say this, but try thinking of this problem like a lawyer and not a technologist. Palm can only get in trouble if:

- they misrepresent their product (e.g., saying it's iTunes compatible when it's not)

- they violated a click-wrap agreement that had contractual language that they violated (and that would make for a fun legal battle)

- they violated the DMCA (which would, likewise, make for a fun legal battle)

- they violated Apple copyrights in some fashion (e.g., they borrowed code from iTunes or from an iPod)

- they violated Apple patents

- they're misusing Apple's trademarks

- they stole trade secrets from Apple

I'm probably forgetting some things, but none of these legal issues are anywhere in the ballpark of "Palm is riding on Apple's coattails". That's not intrinsically illegal. The false USB identifier thing may be an issue with the USB Implementor's Forum (or it's Compliance Committee), but they're not Apple.

So long as Palm isn't using any of Apple's trademarks, and so long as they're didn't use some kind of insider information from Apple, then there's nothing legally wrong with what they've done. If anything, they're doing their customers a favor by being plug-compatible with a popular tool for managing tunes.

Again, I fail to see any reason that Palm owes Apple anything. If anything, Apple should try to encourage other media players to offer similar levels of compatibility with iTunes, rather than potentially getting itself into an anti-competitive position by tying iTunes together with iPods.

(Arguably, they should also let iTunes purchase tunes as easily from other stores as from the iTunes Store, but I don't see that happening any time soon, unless somebody like the EU antitrust busters comes after them.)