Though I'm not a huge fan of the F-35B, I would be very impressed if the USMC was able to keep to this milestone of the timeline. I was surprised when they were already setting up the FRS at MCAS Beaufort. This article also says that the USMC is planning on buying 80 F-35Cs - which I had never heard before.

Marines: We’ll Deploy F-35 On Time - AVweb flash Article