For now Norwegian Air Shuttle has flights to four UK airports and I think it will stay like that the next couple of years. Any further expansion in to UK we need to wait for the arrival of next generation of narrow bodies (737Max and A320neo).
More interesting was yesterday's press release:
"
Norwegian and Virgin Atlantic with Dreamliner Cooperation
Norwegian Long Haul has signed a Memorandum of Understanding (MoU) with Virgin Atlantic. The agreement enables Norwegian to tap into Virgin Atlantic’s expertise on long-haul operations, while Virgin Atlantic’s instructors will receive pilot training on board Norwegian’s brand new 787-8 Dreamliner. Norwegian’s first Dreamliner is due for delivery at the end of June."
Source:
Newsdesk - Norwegian