What's the alternative to the M1911, the M9? Ugh.
I'm sure the sidearm isn't that important in today's military, but a Glock (or similar) .40 S&W would probably be a much better tool Even if they had to stick with 9mm.
I've heard the 1911 is kept around by Special Forces types who can use whatever they want for the most part. Same reason it's used by SWAT teams and such.