Probably won't happen, but it is nice to dream. What with the success of the Marvel movies and the bringing together of characters in the Avengers, it would be cool to see something similar done with the Star Wars universe. Dark Horse did the Vector storyline a few years ago with a story which crossed four different eras in the Star Wars timeline (Knights of the Old Republic, Dark Times, Rebellion Era, and Legacy Era). It would be cool to see some stand alone movies that either did something similar or along the same lines but maybe in the same era. And they could be all original characters or original stories drawing on already established characters.
As much as i am looking forward to the new trilogy, I am looking more forward to the one-shot movies promised about about other characters in the Star Wars universe.