The US Air Force got their first regular F-35 Lightning II on July 2011. Now it's the US Marine's turn: they just got the first two production models of the F-35B, the variant that allows for short takeoff and vertical landing.
The two planes—BF-6 and BF-8— have joined the 2nd Marine Aircraft Wing's Marine Fighter/Attack Training Squadron 501, which is located with the host 33d Fighter Wing at Eglin Air Force Base in Florida. The STOVL F-35B will progressively substitute their current Harriers.
The 5th generation combat jets arrive to the base after Lockheed Martin and the US Navy performed extensive testing on the USS Wasp off the coast of Virginia. They used two test F-35Bs, named BF-2 and BF-4, which successfully completed 72 short takeoffs and 72 vertical landings during three weeks of trials.
The production BF-6 and BF-8 may never see combat, however, as they "will be used for pilot and maintainer training at the new F-35 Integrated Training Center." [Lockheed Martin]