Apparently from the final issue of "under the hood" arc:
http://forums.comicbookresources.com/showthread.php?t=33267
Maybe I'd care a little more if they didn't hint him every five issues or so.
But they don't need the money, they have already made craploads of money from queen.
My guess is boredem combined with the fact that they can't think of anything original.
I hope this isn't another crisis, issues do not need rebooting. The cover looks great though, and seeing how the green Lantern there is Hal, maybe bats is holding Kyle? I don't buy that being nightwing.
Other good stories that haven't been mentioned:
Spider-man: Death of Harry Osborn, Death of Aunt May and Death in the family.
Green Arrow: Archer's Quest
Batman: Dark Victory and Pushback (guilty pleasure)
Daredevil: The Man Without Fear, Born Again and Hardcore.
Worst: Right now sins past.
The problem with the Top is that he wasn't really mentioned in the actual IC issues, I doubt anybody in a tie-in will be the killer because not everybody buys all the tie-in issues.
It came out in the form of the Street Fighter Anniversary Collection this year. What's the problem? Unless you had a dreamcast or owned an arcade cab there wasn't any way of you obtaining it.