...It reminds me of when DC Comics came out with a (really great) comic book series about the Gotham City police detectives, but it wasn't until after Gordon had retired and Bullock quit in disgrace. There were two huge holes in that cast, and I feel the same way about the post-Nemesis TNG books (as great as I think they've been).
Gotham Central. Montoya was great, but i agree on the Gordon front. As far as i remember, Bullock eventually showed up. Great series. Too bad Dan Didio never lived up to his promise to not cancel the book while he worked for DC Comics.
As for Data coming back...I miss his presence in the TNG-verse and I'd love to see him again, but with that other character already coming back from the dead this year, it may be overkill..