[sorry for my English]
Only Obsidian still can create true RPG (Bioware? Bethesda? Are you kidding?), so I'll deposit money surely! I already have all their games and I really love these games!
Of course, I want to see something really big and thorough like sequel Planescape, Arcanum, NwN2 (more like Mask of Betrayer), Alpha Protocol, or something in LotR-world (but not in Third Age, more like closed 'White Council') or even full version of KotOR2 (without cutting of script). But I can not even imagine how many cost license on these titles or 'worlds' and how many costs production of such big project, so will be created something new and independent.
I only hope that new game will be interesting and qualitative like others Obsidian's games. Steampunk or fantasy, present days or fantastic - no difference at all if created world is live - logical and 'realistic', full of interesting personages (with lot of dialogues) and many abilities/choices and proposes his own mechanic of personage's evolution. Isometric or not - only your decision too (but isometric is cooler!). As for me, I should like to see something in Arcanum or Planescape style and without 'dialogue wheel' (of course if new project will not be Alpha Protocol 2)