I've never bought a gun in a smaller/less potent caliber because it was offered in a more-potent caliber, nor have I heard of anyone who did. I put a few rounds through a S&W 500 magnum once, and it didn't make me want to rush out and get a S&W 686. I also once had both 9mm and .40 cal. M&P Pros, but I got the .40 because I liked the 9mm I already had so much. Once I got the .40 I found that I liked the 9mm version better, and later got rid of the .40.

While S&W once offered a 610 revolver and the 10XX series of semi-autos -- I once had a 1073 -- there aren't ANY 10mm weapons in the current S&W catalog. You WILL find a bunch revolvers that use potent rounds: 41 magnum, 44 magnum, 44 S&W Special, 454 Casull, 460 S&W Magnum, 500 S&W magnum and 500 S&W Special.

While the 10mm enthusiasts here on the forum really want an M&P in 10mm, I think S&W is far more likely to say, "been there, done that" and spend their development and marketing money elsewhere.