Planescape Torment was by far my favorite (after BG1/2 of course).
On this matter, it makes me think that there was an image with a message when the EA started... it was : "Gaters are going to gate" (is it what Swen was referring to ?) There are also rumors about the planeshift artifact... And in one of the last trailers, there was a strange creature which reminded me of another version of the Lady of Pain... I do not expect a direct connexion with Sigil, but I hope/expect there will be a good chunk of planeshifting
