If I am not mistaken, the Kimber web site indicates that the Marine Special Ops units are already using Kimber 45ACP's
Before you get all exicted, remember I said "if I am not mistaken", I might have read it on the Springfield sitel....I'm just too lazy to go look again.
In any case, I don't think that the military in general is going to replace the Berretta any time soon. Buying a few .45's for special purposes is one thing, buying a million is another. Yes, the .45 has it all over the 9mm in stopping power but the Berretta holds more rounds, is VERY reliable and a solder can carry more extra ammo with less weight. It is just like the notion that the miltary will return to the .308 or some other "old reliable" heavier round, it is plain not true. Ask any soldier if he would like to carry 200+ rounds of .223 or half of that in .308, almost all will opt for light, more and fast.
As for the pistol thing, most never leave their holsters in combat except for special ops units. For all practical purposes, the 9mm Berretta is a great pistol.
Having said all that, I don't own a 9mm, most likely won't ever as I am a 1911 man and always have been. However I am practical and ex military and have worked with both.
Dana