Theory - The Craig era was a complete "alternative universe" story
From Dr. No to Die Another Day, the series was a continuous, loosely associated story arc. And, although five different actors played Bond, they were the SAME character. Come 2006, we get Casino Royale and a complete series reboot - Bond isn't even a Double-O agent yet. Now, with NTTD, the story and character arc is complete.
Does the series return to the "regular universe" with the next film?