In the established Batman mythos, stuff doesn't start getting really weird in Gotham until Bruce Wayne dons the cowl. The appearance of a masked vigilante patrolling the streets inspires the criminals to up their game, leading to the suggestion that the city might've been better off without him, as arguably without the Batman none of those colourful, psychopathic supervillains would've shown up. Things are a little different in Gotham, since many of those bad guys have already shown up (some of them towards the start of their careers, some of them reasonably fully fledged), and with episode three the city has seen its first vigilante: the Balloonman. Doesn't quite have the same ring to it, and the premise is pretty silly - a guy tying weather balloons to baddies, letting them die in the stratosphere - but it sets a precedent. Obviously it's going to be a while until the Dark Knight himself appears on the scene, but don't count on a complete lack of vigilantes from the rest of the show's run. The young Bruce Wayne is unlikely to be the only member of Gotham's population inspired by the Balloonman's actions - heck, even Harvey Bullock was pretty supportive of his actions. Right up until he killed a dirty cop, anyway. Gotham doesn't have a whole lot of heroes that aren't spun off of Batman, so if there are any more citizens taking the law into their own hands, they'll like be original creations; still, the GCPD could do with all the help they can get, if the series keeps introducing villains at the rate it currently is.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/