I wish Lucas had put the scene at the start of the first film with Luke and Biggs in (especially as he added their scene just before the Death Star battle). I know that it was filmed because I used to have it on an old Star Wars CD-ROM on my PC. I think it makes the scene where Biggs dies at the end even better, as well as Yoda's comments about Luke craving excitement and adventure and never having his mind on where he was and what he was doing (read the novelisation if you don't know what I'm talking about, the scene is in there).
They have QuickTime versions of the cut scenes ripped from the Behind the Magic CD-ROM
here. Well worth downloading. They also have a RealMedia copy of the Star Wars Holiday Special.]