Oh, and a subject that hasn't been brought up yet. Will any other Ranma characters join Ranma in the Pokéworld? I hope not. That's in my opinion what often kills a crossover when people think it's necessary to bring the whole NWC over.
But I'd like to see some scenes of Genma going to the Tendos and how life is treating him now that Ranma's gone. And is the time flow the same in both worlds or will Ranma come back at the same time he disappeared (if he should return to his own world)?