I think the two most interesting are the interviews having to deal with Gotham Central and Superman. (Some of the content of Rucka's Superman interview makes an interesting compare/contrast with some of Brubaker's about Captain America.) One passage re: Superman:
With Batman, when you get him right, you’ve got him. Batman is such a character that the multiple interpretations of Batman all pretty much work – they can all coexist. Everybody works from Frank Miller’s template and go their own way, but they all know what point they’re starting from. You can write a Batman line five or ten different ways, and it will still read like Batman is saying it.
You can not do that with the Joker, in contrast. The Joker, you have to write spot-on, or he fails. Superman is the same way.
I think that's far more right than wrong -- Superman is harder to write than Batman, for a myriad of reasons -- but I think that going on from there Rucka makes a mistake in defining Superman's essential character too narrowly, and that he does so for reasons that have to do with what Brubaker says he's going to try to avoid in Captain America. And I think that ultimately doesn't serve the character or the material -- or, frankly, the writer. Let alone the audience.
Will post more on this when I have more time.