"Only the Good Die Twice" is a spy story set within the fictional James Bond universe. Through the prologue, it is revealed that the name "James Bond" is the codename for agents with 007 status and that the original James Bond from the Cold War (played by Sean Connery in a returning role) has gone rogue and is now the head of SPECTRE. The current Bond is tasked by MI6 to stop him before he can initiate a global thermonuclear war.
I would have preferred Daniel Craig's Bond go rouge like Sean Bean did in Goldeneye and they call on Sean Connery to save the world.... again. haha. But fantastic idea!
It's not a prequel, it's a reboot which retconned all films prior to Casino Royale. So it would still be possible, but Connery would not be the same 'Bond' that he was in the older movies. He'd be an alternate-Universe Bond which just so happens to be played by Sean Connery, who is not connected to the Connery-Bond we all know about in real life.
True, true. I just thought that it was a prequel series since, in Casino Royale, Bond wasn't a 00 yet. But nonetheless, having those two meet would be pretty awesome.