Unfortunately until someone figures out how to support itunes (or some kind of fake mass-storage) on the device, I guess you will have to bug Apple to support common protocols. And especially ask them not to break things like the existing 3rd party mtp apps.

You could still try this : http://www.android.com/filetransfer/

I know it says android file transfer, but it actually is an mtp app as Android these days has dropped mass-storage too. But I have been told the latest OS X update broke it. (I cannot tested it since I do not run/have broken-by-design software/hardware)

Otoh you could run an ftp/http server on the device and access things like that. At least http and ftp is something that Apple will not break.