but is this the beginning of a whole new Batman series?
Yes. This is the beginning of a new movie franchise. The others no longer count. The whole cast and crew is signed on for three.
The next one will be mostly based on the the graphic novels 'The Killing Joke' and 'The Long Halloween', meaning that the primary villians will be Joker and Two-face, at least as far as I know from preliminary rumors based on words from Chris Nolan and Christian Bale.
Yeah, this was a great foundation for a new series of movies. I am pleased.