Akai Professional have announced the SynthStation 49 for the iPad.
http://www.musicradar.com/news/tech...tation49-ipad-midi-controller-unveiled-358474
Working seamlessly with Akai Professional's heralded SynthStation software, SynthStation49 provides unparalleled music creation capabilities, including direct in-app MIDI recording from its velocity-sensitive keyboard, nine MPC-style drum pads and array of transport controls.
In addition to its integration with the SynthStation app, SynthStation49 is also completely iOS CoreMIDI compatible, making it instantly compatible with dozens of music apps already in the App Store and hundreds more on the way.

http://www.musicradar.com/news/tech...tation49-ipad-midi-controller-unveiled-358474