Another thing I noticed perusing the pics from Marjah were a few M-16A4s sporting silencers.
Clearly the one pictured above is attached to a designated marksman rifle, usually a match-barreled M16, and you can tell because of the bipod attached. This looks like a TAC orANGLICO team given the radios, satcom unit and the repurposed Javelin CLU (see full-sized photo), but the caption just says they're grunts from Charlie, 1/3.
We're seeing silencers more and more in Army and Marine kit, but not as often as I'd expected nine years into a counterinsurgency fight. The Corps talked about the suite of gear that would be fielded to help a "distributed operations" configured unit, including silencers, but that initiative hasn't accelerated at the rate many had hoped. The Army has fielded some suppressors in its M110 7.62mm sniper rifle and I've seen shots of Rangers and SF bubbas with them, but none with the general purpose forces.
According to the latest edition of PEO Soldier's portfolio, I can't find anything about suppressors for the general purpose forces other than for the M110.