Pretty sure this has been passed around quite a bit and quite a while ago here on GAF. Most of us do lament for what could have been, but that games original tech/ideas were WAY too much for the console hardware at the time. What we got was ok, I enjoyed it enough to play through it twice(once on 1999 Mode, FUCK YOU LADY COMMSTOCK), but it was the weakest entry in the series.
We haven't heard much from Ken Levine other than he has his new Ghost Story Studios from a few years back, so hopefully he's had the time to make the game he wants. I know he said they want to figure out how to make a procedural infinite story type games, so whatever that means.