Actually, the change over has been going on for sometime, so many of the dishes that were there when it was called "The Kitchen at Sunset Grill" are still there and mostly what you'll notice is the change in decor (which is nice). Also, the closed of Emack and Bolio and moved the entrance to The Kitchen.
If you remember the original Sunset Grill from when HRH first opened, the change is really BIG.
They lured the chef (can't remember her name now) from Disney and she created a really interesting menu. But it seems like it didn't appeal to the families-with-kids crowd the hotel wound up attracting. So changes were made. The original chef is now back at Disney, at Jiko.