Action Comics - Main Superman book with backup features for Super Family characters
Detective Comics - Same as above
World's Finest - Super and Bat family team-up book
Wonder Woman - Solo adventures book
Heroes Inc - Wonder Woman and X hero team up book
The Green Lanterns - Similar to Morrison's "season" approach on the current The Green Lantern only each Lantern character switches out each season. Annuals would be dedicated to the alien lanterns
The Flash - Flash family book, maybe similar to the above Green Lantern book, with a new Flash charater getting a focus each arc or "season".
Aquaman - Solo adventures book
The Brave and the Bold - Green Arrow/Black Canary and X hero team up book
Shazam: Earth's Mightiest Mortals - Shazam family book
Static Shock - Solo adventures book
Justice Society - Set on Earth 2 during the 30s and 40s with backup features in the modern day of that world
Legion of Superheroes - Team book
Black Lightning - Solo Adventures book
The Titans - Standard lineup I suppose, maybe move some of YJ characters here
Nightwing - Solo globe trotting adventures book for Dick Grayson. Not under the Bat-family books
Birds of Prey - I guess the movie lineup but chuck out Harley Quinn.
Blue Beetle - Jaime Reyes solo series
The Blue and the Gold - Booster Gold and Ted Kord Blue Beetle book
Books of Magic - Anthology series for DC's various magic characters.
Justice League wouldn't be an ongoing, it would be mini-series published each year that take the place of event books. Lineup would shift around a bit each time (mainly that whoever the Green Lantern or Flash is would change each year; Hal and Barry one year, Jon or Wally the next, etc, etc)