I haven't read DC Universe #0, and I don't intend to for a while. Trying not to spoil it for myself is interesting ... Newsarama did a pretty good job leaving the spoilers until after the jump on Wednesday, though now they've got a somewhat telling teaser image on their front page to go along with their Dan Didio interview. And don't get me started on the DC Comics site itself, which blasts "Spoiler Warning" while simultaneously mentioning which comic factors into the spoiler, basically revealing the whole thing right there.
So, I don't know what happens in DC Universe #0 ... but let me say this: it's always kind of troubling when Batman, Nightwing, and Wally (the Flash) West stand side-by-side. Batman and Nightwing are OK -- it's the Bat-Family. Batman and the Flash are OK -- it's the JLA. But when Batman, Nightwing, and the Flash stand side-by-side, you're reminded that Nightwing and the Flash grew up in the Titans together, and that the Flash and Batman aren't contemporaries. And that just makes Batman seem really old.
Like I said, haven't read DC Universe #0 yet. But if what happens is what I think happens (and didn't that already happen, in last year's crossover?), that's my argument against it. Because when Batman, Nightwing, Wally West, and you-know-who all stand side-by-side, then it makes Batman and you-know-who seem really, really old. And that's never good. That's all.
(Postscript: And then, even as I'm writing this [Thursday], I just read a New York Times article about Free Comic Book Day, and spoiled the whole thing for myself right there. So there you go, spoilers happening live. Only took two days. Rats!)