parawing742, that's good coming from someone who can't decide how to spell their own name
Try being a little less rude to forum members please, you'll find people value your comments a lot more. In return we wont mention that there should have been a comma after 'specifically' too loudly...
Now to the actual question. This is a little like asking how long is a piece of string.
Compiled languages are faster at most tasks, but speed isn't really a big problem in these kinds of apps. Looking up ID3 tag data and enumerating large numbers of files will take the same time if you do it in c/c++ or java/python/perl etc. Its only cpu bound operations that are affected by the language.
The answer really depends on what you feel more comfortable writing in. Compiling java down to native op codes - using gcj for example is one way if you are happiest using java.
Any of the languages mentioned are going to work out fine, c/c++ is the most flexible, but then the question is which widget lib to use.
I would pick, as xcar suggested, c++/QT because that's a great combination.
Then again, I'd probably go geeky and use curses which would be very cool in a car