The thing is . . . Year One isn't really a Batman story at all. Even though it chronicles Bruce Wayne donning the cape and cowl, at its heart it is a story of a good cop in a bad city; a certain Jim Gordon. In Year One, a great partnership is born; one between Batman and Jim Gordon.
This features quite prominently in Nolan's trilogy, especially in Batman Begins. But, while it covers the main beats of their relationship, I never felt it was explored enough. However, in The Dark Knight Rises, Nolan kind of made up for any Jim Gordon shaped holes left in the previous films with someone new entirely; rookie cop, John Blake (played superbly by Joseph Gordon-Levitt).
In The Dark Knight Rises, John Blake gets a story arc prominent enough to serve as the Batman-working-together-with-a-good-cop element for the entire trilogy. They have a similar background (both orphans etc.), they both want to do the best for their city, they both think that the GCPD aren't doing their job well enough, and, in their own ways, they take matters into their own hands. Jim Gordon sees this as well and recruits Blake to join his underground squad trying to save the city.
The trailers never really mentioned Blake and neither did any of the other promotional material, but we get a real focus on the character; the similarities between him and Bruce/Batman, the mutual understanding (the ‘orphan smile’ in particular) and the fact that he basically becomes Batman's man on the ground (even more so than Gordon). Batman obviously sees something in Blake, as confirmed by the glorious final scene in the movie. This was hinted at when Batman suggested that Blake wear a mask to protect those he loves, and, as early as last year, rumours were flying around suggesting that Blake was going to become Robin or Nightwing or any other side-kick.
One of the many predictions I made about the story was that Blake was going to become Nightwing, as Nolan had previously said he would never feature Robin in one of his films. And Nolan was telling the truth; he never used Robin. But he did use John Blake, a man willing to fight for his city without the protection of a mask.