Couple of news items:
The GAO released their latest F-35 program report: http://www.gao.gov/assets/690/684207.pdf
They state they believe that the program won't finish testing until May 2018 and that such a delay would cost $1.7 billion. The GAO also recommends that the Block 4 Follow On Modernisation program shouldn't release an RFP until testing is completed.
The Pentagon disagrees with 2/3 recommendations; the first is that the additional cost and time needed to complete development should be reassessed; the DoD says they've done that comprehensively and stand by their October 2017 / $532m estimate. The second is that the Block 4 FOM RFP should be delayed; the DoD says this would cause undue delays, lead to a capability gap and infer that it might or would increase costs. The third recommendation is that they should finalise the details of DOD and contractor investments associated with an EOQ purchase in FY2018, and submit a report to Congress with the FY 2018 budget request; the DoD agrees, but only partly, as they've already finalised the details and are submitting the report soon.
The second bit of news is that following their arrival in the UK, 2 of the 8 deployed USAF F-35As have deployed further, landing (wearing luneberg lenses) in Estonia / ~200km from Russia's border today: http://www.washingtonexaminer.com/us-f-35-jets-land-in-estonia-for-exercises-in-putins-backyard/article/2621178