Smith & Wesson recently introduced the M&P Pro Series C.O.R.E. handguns through the S&W Performance Shop. The Pro Series C.O.R.E. have the ability to accept a number of different compact red dot optics. This adds S&W to the very short list of manufacturers who have offered their handguns configured to accept an RDS from the factory.
The M&P Pro Series C.O.R.E. handguns allow the user to mount the following RDS: Trijicon RMR, Leupold Delta Point, Jpoint, Doctor, C-More STS, or Insight MRDS. There is some speculation that the mounting system that allows all of these various optics to be mounted is similar to the Atom Mounting System from Unity Tactical. However, it appears that the optic sits a bit higher with the S&W mounting system.
The trend toward mounting RDS on handguns certainly seems to be gaining momentum.