It is certainly coming on well, but there is still a lot to be done. I know that it is a complex project but I am surprised that they've not done more since I was last at the park well over a year ago now. Are Disney running the project?
Just to be pedantic I'll say there's been a lot of progress in the past year - the concrete pit it took them so long to create has now been built up. As these pictures from exactly a year ago show.
Back to now though things have really been picking up recently as the final section of the site is being worked on (since they have been building from the corners back towards the street for access purposes + this area was being used for storing materials and the underground level had to be completed first too) the last bits of track are being installed and the hotel's concrete structure has been going vertical - so far gaps have been left where the rooms will be which surports the theory that the "tube rooms"/capsules will be prefabricated and just slotted into place.
According to PhantaFriend's Tobi there is currently around 1167m of track in place; and therefore F.L.Y. is now the longest Flying Coaster in the world. He estimates there is about 70m to 80m left to be installed.
He also posted this picture of the final piece of the curve before the brake run being lowered down into place. This means there are now only two gaps in the layout.
Unless they need to leave a gap for a while longer for access purposes to construct something else; track will likely be completed within the next week.
Of course the coaster being finished is only one piece of the puzzle. Presumably there's still a few more buildings and theming structures to knock up inbetween the layout, theming and the hotel of course.
Also I just noticed it wasn't previously mentioned here that the park filed back in February a trademark for a restaurant in Rookburgh called Uhrwerk (German for Clockwork).
Whether this is the presumed restaurant forming in the hotel building (on the left further back in front of the white facade with the slopped roof where track passes closely by above) or another elsewhere in the area is unknown.