Yeah, the most important ingredient for any movie to be good, regardless of what it's based on, is to have good MOVIE people involved. That's why I'd rather have a Spielberg or Bruckheimer as exec. producer on ANY comic-based movie than a Geoff Johns or other person coming out of comics.
Y'know...I'd rather see Timm do something with Pixar, like Brad Bird did, then maybe migrate towards live-action. I also wonder if Timm can do anything outside of DC/comic characters. Has he/can he come up with or develop original characters and stories like Bird? I mean, yo look at how much time Timm has spent with Batman, Superman, and the JL...but then Bird made what was arguably a better Superman(-ish) story with Iron Giant...and one of the best moving-format superhero representations with The Incredibles. I put both of those considerably above any feature-length efforts we've seen from Timm...but granted, he may have not had as much money/resources (strangely, with how big WB/DC are).
I mentioned years ago that WB could have developed their own 'in-house' version of Pixar like Dreamworks has tried to do...but anchor it with their DC characters and Timm. But they keep sticking with cartoon-like releases with more limited backing and release.