I have not read all the comments, but I just wanted to weigh in and say I registered here solely to show my support of this idea.
I've greatly liked every single Obsidian Games so far, and I love the old school isometric games - stuff like Fallout, Baldur's Gate, Arcanum, Icewind Dale, Planescape Torment and so on.
I trust the creative vision of the good people at Obsidian - but I would absolutely LOVE a new isometric, party-based crpg of some kind. The specific setting is not important to me as such (I love Planescape as a setting, but the way I see it Torment does not need and never