I can't remember this on the dvd if they mentioned it, or don't know whether this was a wild rumour at the time, but I remember something in Total Film magazine in 1999 with Sean Connery as Gandalf and Stuart Townsend as Aragorn.
ST actually started filming as Aragorn, but (AFAIK) while various names - including Sean Connery - were being bandied about as Gandalf, Ian McKellan was the only person actually cast.