I say go for it.
However, I don't see the character's inclusion being conventional in that he'll be adopted right after the tragedy at the circus; I think that Bruce's life in the sequel should be too hectic for that. I'm going for something unprecedented, introducing both Richard Grayson and Jason Todd at the same time. I posted what I thought should be their story in the sequel in the "What Do YOU Want in the Sequel?" thread (link:
http://forums.superherohype.com/showpost.php?p=16365799&postcount=293):
Why include Robin(s)? First, the story would allow for it. In the sequel, Batman has less reign in Gotham, which causes him to go undercover; this allows for more outright criminal activity and maybe less vigilante activity because of criminal and police deterrence, but those that would remain would use bolder tactics to offset that and Batman's reduced presence. My ideas are at least slightly influenced by the
B:TAS episodes "Robin's Reckoning" and "Shadow of the Bat" in that they involve Robin striking out on his own for revenge, the drama that can occur while undercover (Batman's dilemma), and possibly Commissioner Gordon being targeted by criminals.
I see that many would like to see this movie's final scene occur at Wayne's parents' grave site. I think that coupling Wayne with Grayson at the site would produce a moving scene as well as a (if not
the) key bonding experience for the two. If Deathstroke is involved in the movie, that should also heighten the drama and enrich Grayson's story.
Second, this hasn't been done. Grayson's been seen on film, yes, but Todd hasn't been seen in anything beyond the comics other than a caricatured drawing on an episode of
Teen Titans. Some might be thinking, "...and for good reason," but I'm thinking that his character, in tandem with Grayson, would bring an interesting dynamic to the film and give viewers something they haven't seen before: not only Grayson being a vigilante prior to being "Robin", but him working with Todd and the plain inclusion of Todd's character. Having them work as a team should also produce intriguing action scenes, perhaps with them using Parkour to evade their enemies.
Third, Robin is an important part of the "Batman" mythos. Like many have said, Robin brings a certain humanity to Batman that keeps him from being completely cold, which is a road that I think he may head down in the sequel given that his circumstances are the way that he and Gordon describe at the end of
TDK.
Furthermore, I don't think that Nolan is averse to including Robin(s); some might have taken them the opposite way, but I took the fake Batmen in
TDK as a foreshadowing for Robin(s) and slightly modeled how I think Grayson and Todd might be after the way that the fake Batmen operated (though with more stealth and different costumes -> CORDURA® fabrics, Kevlar vests, face-concealing masks, etc.).
I think that if Robin is depicted in this fashion or something similar, his character would fit the more grounded, verisimilitudinous nature of this series.