Ballsy as hell indeed. Yeah, there’s obviously potential in that, as well, but I really don’t think it’d be treading water. I mean, if you think that the whodunnit is the point of the original novel, it’s pretty much all treading water, too - it takes forever to get from A to B, and that’s although it’s actually a pretty straightforward mystery. So I would like to see a show doing the same thing the comic did: using the murder mystery as a device to flesh out the characters and their history, and the world they are living in.
I do agree you couldn’t do that forever, obviously, but I think it’d easily be fodder for three or even four seasons. And I’d probably still end it at the same point that the original does… or, if it should continue, do that with a restart: leave the old characters alone and establish a new generation of heroes living in Adrian’s utopia who were inspired by the old ones - maybe even a new Rorschach, in the same way in which there were two Night Owls. Anyway, they’d be up against Adrian at some point, obviously, and maybe at that point you could bring Dan and Laurie back into the mix.