It WILL be a great aeroplane and has taught Boeing a LOT about how to build a 21st century airliner (including a lot about what NOT to do!!)
While the 777-8 and -9 will be pretty conventional systems wise, I bet the eventual 737 replacement will be basically a mini 787.
HOWEVER, building an aircraft with that many innovations was always going to lead to a long period of teething problems.
The fleet average isn't at 99.5% yet, but the fuel savings are immediate and substantial.
My initial post was just a little reality check toward the posting of what was unmitigated propaganda.