my two cents - PLEASE make another planescape! top-down view, turn-based combat, set in the wonderfully rich planescape universe.
obviously the story from PS:T doesnt lend itself very well to a sequel - that's totally fine. new characters, new storyline, but i want to go back to sigil. i want to find portals to other dimensions. i want to pick a faction, and then drop it and pick a new faction.
Sigil has SO much depth to explore... take us back!! and please, keep it top-down and turn based. we don't need another FPS-RPG hybrid.