It would be awesome if Team Soul did a Star Wars fighting game. As much as I love Soul Calibur, the fighting game genre really needs to be opened up a bit. A Star Wars fighting game with Soul Calibur's gameplay mechanics would do wonders at bringing mainstream gamers back to the fighting game genre.
Right now, fighters are played by mostly hardcore gamers. It's a genre where you pick a character (or two, if you're really hardcore), and get really good at kicking butts with them. And for Joe casual, it's hard to get into a fighter when all the characters are foreign to them, and the story is a convoluted mess that no-one can even attempt to figure out. If you dressed one up with an accessible IP like Star Wars though, it could potentially do for the fighting game genre what Halo did for the shooter genre. Lots of characters that everyone likes, right out of the gate, plus an attractive headline for the box with a story that you can actually follow.
Maybe using Star Wars characters in SCIV is the perfect opportunity to "test the waters" for such a game. If everyone loves playing as Vader and Yoda, I imagine Namco would be at least a little interested in making a game with an entire roster of SW characters.