Here’s what MooCowMusic’s press release says:
MIDI Mobilizer is currently the only hardware MIDI interface for the iOS platform, providing a pair of MIDI cables that can be plugged directly into external devices such as MIDI controller keyboards and modules, or a computer interface to control Digital Audio Workstation (DAW) software such as Logic, Garageband or Cubase.
With our existing MIDI-via-OSC technology, Pianist Pro can already be used as a wireless master MIDI keyboard to control external soft or hard synths. MIDI Mobilizer now allows us to offer a robust wired alternative for live performance, together with bi-directional control enabling Pianist Pro to also act as a MIDI sound source or sequencer driven by an external hardware keyboard. Now you can record your song ideas on the road with nothing more than an iPad and portable MIDI keyboard, and then import those songs into your DAW via a Standard MIDI File when back at the studio.