(SPOILERS) So, Will They Start Over or . . .
bring Bond back in this timeline?
For starters, I've watched the ending several times now. We see Craig's Bond standing in the path of what we assume are high-energy explosives destroying the lair. He's swallowed up in what looks like bursts of fire. The angle quickly switches to a faraway view showing what appear to be more explosions.
What we don't see is his body literally destroyed, which on the surface sounds ridiculous, of course, but this is a Bond movie, and as we've seen in the Craig films, each has gotten a little less terrified of embracing the wilder aspects of the ones previous. It could be a holographic projection of Bond for all we know, or there could be some other fantastic explanation for how he survives.
We also know the Craig Bonds have mixed up or rehashed many of the elements of the previous film iterations, as well as the novels. For instance, the film You Only Live Twice fakes Bond's death, and the novel ends with him presumed dead. In the novels, Blofeld regularly changes his identity to avoid capture, relying on everything from plastic surgery to weight loss to voice alterations, in addition to a host of new identities.
Could this movie's ending set up the next film with Bond occupying that space? That is, if Craig can't be coaxed back to do just one more (it wouldn't be the first time in the franchise history for this to happen), then his successor would be explained as the same character, somehow having survived, but physically altered, perhaps to conceal scars from injuries. Perhaps he's even more youthful for some reason as a result, maybe even connected to the process to neutralize the nanobots or whatever.
I'm not saying this to grasp at straws or for wish fulfillment. It will be easy just to sneer and say something dismissive like, "He's dead, dude" or whatever. That's not my point. I'm looking at it from the writing point of view. In some ways, it may seem like they've boxed themselves in by ostensibly killing Bond, but I don't know that that's the case. Of course they could always just start over -- and Craig will be close to 60 by the time the next Bond film comes out if they drag their feet again making one. It might be quite impractical to make another with him.
But then so much is determined by box office, both in terms of how well NTTD does and how big a paycheck they dangle in front of Craig to return.