Well, this was inevitable. There was no way Danny Boyle would suddenly jet the James Bond franchise with just "creative differences" as the given reason because it's just too vague, and this was not a vague situation. Something of note definitely happened to cause this split, and now we're starting to learn what that was.
According to The Telegraph, there was a rift between Boyle and star Daniel Craig that was just unrepairable. Apparently, that story idea that Boyle and screenwriter John Hodge had that was supposedly so great, wasn't so great. Producers were skeptical, and didn't really take to the modern day Cold War storyline they had in mind. But they moved forward on it, setting aside the script penned by franchise regular Neal Purvis and Robert Wade, which caused a delay in shooting.
However, it's crossing Craig that was the final straw. Craig's power is such that he has vast influence over any casting choices, and he stepped in to prevent Boyle from casting Tomasz Kot as the movie's villain. Note that Daniel Craig is one of three names mentioned in the announcement of Boyle's dismissal, along with Bond power players Barbara Broccoli and Michael G. Wilson.
So that's done...for now, but I doubt it's the last we'll hear of this situation. It's all but a certainty Bond 25 will miss its November 2019 date, unless they find a director to take over the Purvis/Wade script quick.
