Lol, presumably. Actually, you can have your continuity. But, you know what? Casino Royale has to be a part of that continuity as well, since the filmmakers have never stated otherwise.
No, not really.
Casino Royale has two key differences from every previous Bond film - it depicts Bond's origin story, and takes place explicitly after 9/11.
While Bond more or less had a floating timeline from DNO to DAD, there was a constant in that the timeframe was either during the Cold War, or in the case of GoldenEye onwards, explicitly taking place after it (bar the intro). The only way for Casino Royale to be in continuity with the previous films is for something like this to occur:
-Intro scene (where Bond gets his two kills)
-Every Bond film from Dr. No to DAD
-The rest of Casino Royale
This really doesn't work in the context of the film. And if we move onward, there's other things that can't work, such as:
-In Casino Royale, Bond meets Felix for the first time. In the original continuity, they'd met by Goldfinger.
-In Skyfall, Moneypenny is a field agent who retires for desk work. So, what, she started off as a secretary, then went into the field, then went back to being a secretary?
-Back to Casino Royale, M comments that "I knew it was too early to promote you to 00 status." So, what, he was promoted, saved the world plenty of times, and she's having regrets now because he kills a bomb maker? It works in the context of the film, but not in the context of a wider series.
There's at least some argument to be made that every Bond actor started a new continuity, but there's no way that Casino Royale can take place in the same continuity as any Bond film before it. Not to mention that going by the games, different versions of previous events occur (e.g. the Craig!GoldenEye game).