"Let's just say that I don't think our show has very much in common with the book any more"

Kristin Davis' quote recommends that the program she is referring to has actually strayed away from the source product of the book. This could imply that the show has taken a different direction than the book, or that the show has changed the plot and characters in a manner that makes it indistinguishable from the book. It could also suggest that the show has taken a more modern-day method to the story, or that the program has included components that weren't present in the book. Whatever the case may be, it is clear that the program and the book have extremely little in typical. This could be a good thing or a bad thing, depending upon the viewer's opinion. It might be a rejuvenating change of pace, or it might be a frustration for those who were expecting a loyal adaptation.