Return of the 45
Via James, it looks like the M9 is on its way out and will be replaced by the .45ACP. James thinks it will be a Sig.
Update: Tam says Nopers:
The pistol will replace the M9, but only for SOCOM. My money is currently with the USP45, whose dimensions, as it has been pointed out, are suspiciously similar to the max dimensions given in the RFP.