I was most interested by this quote:
P&W get a lot of flack from Bond fans which I always thought was undeserved, but it does seem from this quote that the reboot was the result of their reach exceeding their grasp. Their original "Last Temptation of Bond" idea sounds a lot better, but by their own admission, they didn't have the chops to pull it off.P&W: Our original concept was that it did not need to be a re-boot, and that it could work in the context of the series like this: the Bond we meet at the start of Casino Royale is the same guy that we've always known, a womanizer who never lets women get close - and the reason for this emotional isolation is that he is an orphan who has always fended for himself and not relied on others. But in the course of his relationship with Vesper (who we made into an orphan herself) he suddenly gets an insight into normal life - ie, the possibilities of being part of a family, the thing he has never really known… In OHMSS he married Tracey but he wasn't quitting the job - ie, he didn't give up everything for her… But with Vesper, he knows that to have a chance of a normal life he must give up the career which has always provided his identity and 'family'; and he is prepared to do this for her and the chance of happiness (which he had never expected to happen to him). However, when her past betrayal is revealed - along with the manipulative evil which forced her into it - he realizes that here is a cause to fight, worth donating your life to. In those moments of happiness with Vesper he tasted real life, so he now values the world that he is protecting - whereas before, as Sean, Roger, George, Tim and Pierce, he had done everything just the same, but without understanding in his heart the value of the society he is protecting. So Bond emerges from Casino Royale fully-formed, a man who understands the value of the world that he is out to protect, and the possibility of happiness he is permanently renouncing for himself!
HOWEVER! It was hard to make this very clear in the script, and we all liked the reference in the novel to the two kills that earned him the 'OO', so it was decided to go all the way, show the kills [Yeah, in the fricking pre-credit sequence -K] and start him off again. (The 'philosophical' theory above of course still applies to the character's emotional growth in the film…)