Keep on the Shadowfell, set in Sharn
I wanted to ping interest on this again.
I'd want to start with a short "flashback" dealing with some events during the time when the Keep was whole and in use in the city of Shaarat, the precursor to Sharn, shortly before sections of it were sealed up. Then the adventure proper would begin, though we could always flashback more later, if we thought it would be interesting.
I think that town would be set in the Fallen district, with the ancient keep having been uncovered and unsealed during the fall of the Glass Tower. As a slum, Fallen (called Fallhaven by some, for its having survived - relatively speaking - the calamity on the Day of Crystalfall) would be isolated, compare to other parts of the city, and a death cult could gain a foothold there.
Characters could have dragonmarks. House intrigue wouldn't be a huge focus, but could come into play.