Someone from Boeing told me that it was omitted because they simply built a more efficient wing on the 777. but then how about the positive effect of the winglet reducing wing-tip vortices and drag?
Anyway I found the answer "they don't want to look like Airbus'' was pretty good!!
No offence intended Edwink, just that I hated to think you gave them reasons to put your name in the 'OUT' tray.