Not likely. I would consider that and 10mm nice ideas but are not catching on. It's a conundrum in the fact that the ammo is too expensive and scarce, and therefore causes the popularity to drop, therefore causing the ammo to be expensive and scarce
I believe it is a good law enforcement round. It was designed to have the ballistics of a .357 magnum fired from a 4" barrel in a cartridge that can be reliably fired in a semi auto pistol. U.S. Secret Service and Texas DPS currently use the .357 Sig in their issue sidearms.
However far to many Police Departments have been sold on the .40 S&W and in current finical times no department is looking at making a large switch to a new cartridge.
I see the merit of the .357 Sig and would like to have one, but currently the ammunition cost to much to feed it. Add to that being a bottle neck case it is more time consuming to reload than say the 9mm.