It's brilliant! I saw it back when Darren and Terrance (Graverobber) came through with it on the Repo! Road Tour, and it is phenomenal! I agree, Paris is in the film and is perfect as Amber Sweet and really brought me to rethink my view of her. After hearing from Darren Lynn Bousman how genuinely nice, professional and easy to work with she was, I really am going to push myself to think past the image of her that the paparazzi and news stories propagate.
Also starring is Anthony Head (known for Buffy fame) as the Repo Man. He does a fantastic job of playing such a tormented figure as that. Also in the film are Ogre of Skinny Puppy and Sarah Brightman (as my favorite character (only tied with Grave Robber) Blind Mag). Her voice is simply angelic. Amazing movie and amazing soundtrack.
You are right, Sayday, it comes out January 20th and (keep fingers crossed) there are approximately 60 songs in total, so let's hope for a full soundtrack to be released as well!
For fans of Rocky Horror, Horror, Goth Subculture, Gore, Dark Comedy or Opera, check out this film! And the soundtrack!