Y'know we really enjoyed Planescape, but we thought that all that complicated dialogue would confuse the player so we decided to just make the process of selecting dialogue automated, based on your karma meter, which is also automated. We also decided that the setting, while nice, needed to evolve. So we've moved the whole game to Tamriel, which means that all you Planescape fans can experience horse armor, in case you missed it with Oblivion.
Also, another problem we had with Planescape was that it lacked explosions, so everytime you look at a building, it blows up. Isn't that cool?!