Yeah he can write Bruce being an ass but he showed in Booster Gold that he can write his nicer side too. He's also written Jason pretty good in his brief cameo in Justice League #19. I forgot he wrote some of these guys before but that interaction in the preview? That makes me want to get Forever Evil.
Talk of preview SPOILERS under the cut
Dick and Barbara actually feel in character when there together. The closest I've seen to that since the relaunch was their appearances in DOTF. Although I think Barbara should have been harsher and more demanding given it was the Joker threatening them. But yeah their both likable and are handling themselves more maturely than other writers have shown them. It's annoying on the one hand because every other writer has them react differently. Plus Bruce was an ass to Barbara so you'd think she'd be holding onto that one. When she suggests all of them get together unmasked I wonder if she means Jason too. Mainly because we have very little to base their relationship on in canon.
I know what Bleeding Cool has said and I'm not really sure how the Nightwing theory/spoiler would work. DC has teased similar things with DOTF. I would LOVE to see how everyone: Alfred, Bruce, Tim, Jason and Barbara react to it if it's true.