No, it doesn't allow MP3 via USB from external devices.
Its saying you can't use a USB, but you still can use the same phone, same music, just wireless instead of using a cord.
I wouldn't call that help unless you mean it helped make shyt easier, then yeah. It helped achieve that.
If DLNA app was this hard to find app you had to pay for, then I could see where you trying to come from
But thats not even the case. So this is a non issue. You can't do what your complaining about NOW with the 360 for the most part (lots of apple stuff don't work)
Anywayz
If this feature was really an issue to anyone? Then why would using Play-To be a problem.
You'd think someone who has the know-how to use music from a phone to an xbox would know how to use an APP