I've not read the specs too deeply, but my first thought is "how easy would it be to fuck with someone?".
If there's no real security, it'd be rather easy to, say, dump confidential reports onto the annyingly loud and smelly git opposites USB music device and then call security about their funny behaviour. Admittedly, all you need to do right now is plug the player in, but wih wireless, it could possibly be done while it's in the persons bag.
I'm sure a BOFH would have all sorts of fun incriminating folk.
That aside, I'm glad it's moving on.