Hitfix has the details from the TCAs, where FOX president Kevin Reilly offered a few breadcrumbs worth noting:
Executive-produced and written by "The Mentalist"'s Bruno Heller and produced by Warner Bros. Television, the show won't have "a bunch of characters you've never heard of," Reilly promised. "We see Detective Gordon, before he's a commissioner, all the characters you know, Bruce Wayne, the Penguin, all of them. It's Gotham teetering on the edge, and we see what makes these characters become who they are, [like] Catwoman. It's an operatic soap that has a slightly larger-than-life quality to it."
I've loved Bruno Heller's The Mentalist, and the story of Bruce Wayne lends itself to TV so much more naturally than movies. Dark, gothic, and full of angst works when in the least Gossip Girl-y hand possible. This is something of a pre-origin story, occurring even earlier in the Gotham timeline than Batman: Year One by Frank Miller, or the currently-running re-origin story Batman: Zero Year by Scott Snyder. Heller is what should inspire a great deal of confidence here.