The moral equivalent of running World’s Largest Dungeon for 4e, at present, would be to just run the module series. WotC is gonna put out three modules for each tier; H1 and H2 are the first two for the Heroic tier, and when H3 comes out that’ll get a campaign to level 11. There’ll then be P1, P2, and P3; followed by E1, E2, and E3. These are all announced.
Each module comes with play maps. I mean, come on.