^Yeah man, somebody could re-compile the code in like a day and half at most. I think unfortunately it would not be realized that every MPC fan with an iOS device would buy it, monochrome graphics and all.

Like your iPad would look like literally like a VGA out 3k on the screen. But we would all pay for that, especially if it had all the proper MIDI out features to be used with Camera Kit+MIDI interface, iConnect, docks and so on. Just knowing it's not the graphics or presentation we want, it's the proven sequencing and familiar OS style.
Make it like $5 market as "classic MPC emulation" for the folks that are gonna see the monochrome graphics and be like WTF? (not us of course

) and they could sell a few copies. And it would cost almost nothing to make the app.
I had always hoped OS X's RS-16 app would get ported to iOS, that would be closest we get to the OP's suggestion/dream I think. I just don't see JJ or Akai ever doing a straight port.
And yes andreat668, as long you have a MIDI solution in place for your iOS device it will work with Beatmaker. I have used an MPD32, 4 different MPC's, Korg drumpads...it all works.
One tip though Beatmaker 2 has 8 pad banks, and starts on MIDI note # 1 for pad 1A. So on an MPD you'll need to make 2 presets. One for Notes 1-64, and another for Notes 65 and up. If you need MPC PGM's for BM2 I posted 2 1k/2500 ones in the Tablet Apps thread a while ago.