Even if they did, it wouldn't be something they could do for long. Those voice actors would demand far higher salaries.
I agree. Chris Pratt and Jack Black are going to be very expensive, and chances are may be unavailable at times since they may be doing other movies (especially if Jack has to do any more Kung Fu Panda movies). Same with the other actors (including Seth Rogen, who is also tied to Kung Fu Panda, as he voices Master Mantis, and will also be busy with the sequel to TMNT Mutant Mayhem, as he is producer and the VA for Bebop in the film), so it will be pretty costly even for Nintendo to get the movie VAs to do their roles in video games (plus who will voice Wario and Waluigi, since those two were also done by Charles, but have not appeared in the movie?)
My guess is Nintendo will be holding auditions to find the legendary plumber and his brother and their two evil counterparts a new VA (or four, if they decide on it), but all I can say is, whoever they hire will not match up to the legendary performance of Charles Martinet.