Scott's right, with the technology of today's arrangers and workstations along with MIDI, it is easy to emmulate this style of organ playing. Personally, I think it is even more veratile to use keyboards because each can customize their own setup. If I were ever to add a workstation or synth to my G70, I'd likely add a Motif or something like that. Then I get a whole palette of the Roland sound, and a whole palette of the Yamaha sound. I agree that it might not have the cohesiveness, but the possibilities of what this type of setup can do are endless. Now, as far as classic or real organs go, unfortunatly, the technology does not exist to put these into a keyboard yet. Now of course, they have some stellar organ samples on board, but without sampling every stop and being able to play them in any combination, as far as I'm concerned, you can't beat the real thing.
http://www.youtube.com/watch?v=0gRBCAdC7wI&mode=related&search=