The Batman scores are interesting in that, yes, they re-use a lot of material but at the same time both TDK and TDKR introduce a TON of new music. TDKR especially. Each film kind of has its own musical identity, IMO.
Zimmer answered about how I expected he would. Kind of torn but somewhat interested. I'm glad he mentioned doing a new Batman theme, it's mandatory IMO. I don't want to hear Barbastella pounding the subwoofer when I see Batfleck for the first time. It'd be like cheating an emotional response. The same way it would've been if they had used Elfman's theme for Batman Begins.
I still think Zimmer should consider working with a collaborator to pass the Batman torch to while he stays focused on Superman. Bah, this shouldn't even be an issue. I blame WB for "smuggling" Batman back into it as Zimmer put it.