Some good info available in this Flight Global article from 2 days ago:
F-35 problems on their way to being fixed
In short, F-35 variants have now flown to 49,000 feet, a mere 1000 feet short of the required 50,000 feet envelope they are required to be cleared for, F-35A has flown to Mach 1.6 and B and C models have flown to Mach 1.4.
The helmet will require new camera and inertial measurement units and software tweaks, all of which are in the process of being integrated now and will be tested this summer.
Air restart and weapons testing are proceeding well and will lead to high AoA and live weapons drops this summer.
All sensor, EW, CNI, DAS, EOTS and data-link testing is proceeding very well...