The FAA has approved the design change made by Boeing to address lithium ion battery risks on the 787. The FAA will make a directive on how the fix should be made and it will make FAA inspectors available to expedite the repairs. Boeing has had kits and staff ready to deploy to customers for making these fixes and I would imagine that Boeing has told them “go”.
A couple of observations:
1) Boeing will destroy its reputation for many years to come with both the public and airlines if this fix proves to be inadequate. I would want to be very, very sure and very certain that those batteries are contained against everything short of an act of god. Spin and damage control will not fix that problem.
2) Nothing that I can so far find has any guidance on what kind of ETOPS the FAA will permit with the 787. There was, originally, speculation that the FAA and other agencies would be inclined to not grant enough ETOPS time to be useful to 787 users. If this fix works, then it should not have an impact on ETOPS. If the original ETOPS granted is amended to be something considerably less, then I think that reflects a lack of confidence on the part of the FAA.
I would expect a practical return to service for the airlines being some time at the end of May or the first of June.