Honestly, I doubt it's gonna happen any time soon.

Craig's Bond has popular and critical success (and Skyfall tops it all with most reviewers), and the return to a Bond somewhat more faithful to Flemming character (not exactly IMO, but some fans of the books like my dad perceive it that way) has been fairly well received.

Then there's the zeitgeist, something the James Bond movies always, always aimed to follow closely (they're one of the best series to reflect the time they were made in and to see the evolution of interests/worldviews/tastes in movies). The fashion of the day isn't too fun/light spy movies/shows, might not change for a while. Most of them are fairly dark and tortured (from Spooks to 24 to Homeland, it's really the current vibe). Twenty years from now we'll see the Craig movies as typical of our time, following the vapid VFX extravangaza of the Dalton ones, and the even more vapid and gadgety later Moore phase (which has some of the worst ever made, Moonracker, Octopussy and so on - and the Bond furthest from the books's one).

I've grown up in the house of a massive Bond fan, and I must say the Connery ones were the ones dad and us kids liked the most, we liked less Moore, at least his last ones, and Dalton was the low point for me. So far I find the two first ones with Craig the most interesting ones in a long while. I haven't seen Skyfall, but Casino Royale in particular I liked as I had not liked any new James Bond in ages.