Apple has shown in the past they are not afraid to change leading products to replace them with even better products.
iTunes is facing increasing competition on many fronts now.
If Apple think they can provide better a better experience by separating the Movies and Tunes and running a separate Sync application then they will.
One day, Apple will also have to rewrite iTunes on the Mac side quite a bit anyway.
Re architecting their media software architecture is exactly the sort of thing Apple would do if they believed it would provide tangible benefits for all their customers.
On Mac OS X — Mail, iCal and Address Book work really well together and you can use as much or as little as each application as you want. A similar approach for media wouldn't be wrong in my opinion.
iTunes: I agree that iTunes needs rewriting, especially on the Mac, which would be awesome (I love Cocoa apps on Mac & WPF apps on Windows!
on iPod Touch: Personally, I hope they don't add GPS or any crappy new feature if it means the price stays the same / goes up. I would far prefer exactly the same product (though it would obviously have the plastic back, which I don't mind) but at $250 or (PLEASE?!) $200. If so, I will definately buy one at Christmas when in the US of A (bloody british prices). Then again, I wouldn't mind GPS AND lower prices
Simon