This, in my estimation, is how you fix the DCU:
EIC: DiDio. Concentrates on Hollywood stuff and general big picture. He's been working hard the last five years or so, so it's cool if he just wants to coast and let new managing editor handle a lot of the details.
Managing Editor: Ron Perazza, and I'll tell you why: a) former Marvel editor, b) tons of experience running DC's custom publishing line, c) very well-liked by workers and freelance talent, d) great cultivator of new talent, e) extensive marketing experience.
Superman Editor (aka "Geoff Johns Editor"): Covers all Superman and Green Lantern titles.
Batman Editor (aka "Marts"): Handles all Bat-books.
Quirky Editor (aka "That Indie Guy/Gal"): In charge of aggressively pursuing new talent that can revision classic DC characters (a la "Starman"). This is an important role, because in theory a lot of that is R&D for eventual Time Warner movies/TV. Oh yeah, also -- talented people with unique things to say get work.
Team Books Editor: Justice League/Society, Legion, and Titans books.
Etc Editor: Handles a potpourri of assorted solo books. Give this to an associate editor who looks like s/he has the chops.
Johnny DC Editor: this goes to another Associate Editor.
It is of tantamount importance that all these editors get along and share information.
Incentives should be given to editors to pull in new talent, retain happy older talent, and create cutting-edge new titles. $incentives$ should be given.
And if any editor is caught saying they are tired of being there, are jaded, are just going through the motions, etc., go find another editor. You can't afford jadedness.
On the topic of assistant editors: an assistant editor should be the next generation of editor for your company. Hire and reward accordingly. They are not glorified administrative assistants.
All the books that have been f**ked by extreme creative changes, etc -- axe them and start clean.
As for the continuity between Final Crisis and the build-up -- that's completely f**ked, so don't even worry about it at this point. Just move past that.
And the most critical element: Making DC's books accessible - top to bottom - increasing their casual and ongoing reader base.