I don't know how interested I would be seeing John Blake continued in a book/movie. I don't know how that would work, I feel like he would get killed his first night out in the suit, but then again I'm not saying it couldn't be done.
As far as Nolan's universe goes I did really like the Gotham Knight animated movie set in between BB and TDK. Sure Gotham Knight had it's problems but there were six different anime directors on that one film. The anime styles and the darkness (or little more adult than some of animations have been) was appealing to me but that's just me. I would really like to see a anime or a comic set up like the Nolan universe but with a little more of the fantastic included (i.e. Mad Hatter, Poison Ivy, Clay Face, Mr Freeze to name a few)
If anything I would love to see a prequel Catwoman story to The Dark Knight Rises.