Ping!
This is NOT news for any current or former serviceman or one who watches the industry.......I spoke of this here when SIG and S&W came out with their clones......
SIG and S&W both come out with a 1911 variant, Springfield, Kimber, etc etc etc all pay their bills with the 1911 variants and even glock came up with a PC flavored 45GAP version that will allow the petite handed troop be they female or male to use the glock 17 size frame w/ a glock 21 sized frame and a ballistic clone of the 45ACP round albeit a "shorter" round to fit the smaller framed handgun.
Albeit the 1911A1 is my favorite I also pack a glock 21 or a SIG 220 on occasion to fit the requirements of some PC organization that would not allow the 1911A1 platform.
I'll suggest that the SIG 220 gets the official nod for replacing the M9 Beretta due it presence in the system for spec ops and aircrews in the 9mm flavors. But the system for selecting the firearms issued is fickle so anyones guess is possible........
SIG220 if the 1911A1 design is passed on.......is my first guess for the replacement of the M9.