Like how I sucked you in with that title right?
According to the Rama there's been a bit of speculation as to who the dead hero is that will kick off the Trinity War. As the article mentions everyone from Martian Manhunter to Wonder Woman is being considered.
While that would really suck and I would never forgive DC for such an egregious wrong doing, I don't think it's her lying in the casket. While the article continues to search for clues as to who the would be dead guy is, they reflect on this promotional image or wrap around cover for further information.
One other factor that gave me pause is that Johns mentioned that the relationship between Superman and Wonder Woman would end badly . . . like death badly? . . . NAH. Even that's too low for them.
Wup there you go, Wonder Woman may not be front and center but she certainly is front. The likeliness of her being the one to bite it in this event is highly unlikely as she's shown here giving Constantine a good time. Perhaps speculators that feel that it might be Diana are also haters of the character to begin with and want nothing more than to see the end of her. . . . but that's just conjecture on my part as the article continues to sight inconsistent interview points that Johns makes against official DC solicitations for upcoming titles involved in the event.
Another hint at the identity of the fallen is that the cover of the flag covered casket is that of the JLA #5 cover with JLA members reaching out signifying that the coffin contains one of their own, not an Original Leager or a Dark Leaguer.
So for the Wonder Woman haters that, for a moment, thought that she would be worm food at the start of this I hope the back cover of the comic doesn't slap you in the face as you close it on the final chapter. Not only will she survive but I'll bet that she saves the whole effin' planet all by her lonesome . . . . again!
END OF SILLY RANT.