Thanks to my friend Steve Pegram for passing along this incredibly interesting thread on the AR15.com Forums: "USMC after-action gear assessment". Pay particular attention to the reports on the adequacy of 5.56mm vs 7.62mm carbine/rifle ammunition, and the spectacular satisfaction of operators with their M16 & (especially) M4 carbines.
Especially interesting is a point I've known all along: a lot of issue military gear quickly gets replaced with individually selected commercial "sporting goods" equivalents, e.g. Panoptx goggles replacing the awful issue crap.
Another interesting point: the M9 pistol still sucks. It should be replaced with the Glock or whatever the individual soldier wishes to otherwise carry.

I'll address the point about the individual soldier later (I'm getting ready to run out now), but as for the 9mm thing, I can't disagree more... why? The .40S&W is a vastly superior, now widely-available American replacement for the obsolete 9mm.
It's interesting to note that individual operators, when they have a choice, usually drop the M9 like a hot rock and field a 1911 or a Glock... .45ACP or .40S&W.
ooo rah
I agree about the M9. I can't for the life of me understand why the military would EVER empoy a 9mm in combat situations. Sure, some people make the argument that the M1911 was too old and feeling its age, but still. I mean, Law Enforcement stateside are often outgunned with their measly 9mm's, can you imagine in a warzone, when a soldier is forced to use this BB Gun of a pistol? Against enemies wielding AK's and God knows what else? It's ludicrous.
At least The Navy had the sense to issue the HK Mark 23 Socom .45 as it's standard-issue sidearm.
I know I'd feel a lot more comfortable carrying a gun that can drop a man with a single slug to the chest, rather than one that'll take 8-9 shots to down my enemy.