"At the ripe old age of 57, Roger Moore decided to take one more turn as England's favorite secret agent, James Bond. The result was 1985's A View To A Kill, the 14th movie in the Bond canon."
Daniel Craig, age 47, is contracted to do one more. So, when he is 50, they will do the next one......unless the rumors about a double feature are true, which would mean he would be still be 47 at the time of filming #25.
Credited source or not, even if Craig HATES the character, even if he gets a doctor's note. He HAS to do one more.
Everything else is speculation and rumor.

for the next version of Bond, find a early 30's actor and lock him in a 5 feature deal.