I'm not saying it's the be all end all, but if Summer League was his chance to audition for the backup point guard spot then he certainly didn't do enough to convince the coaches that he was ready to take the reins, hence they signed Miller.
What cracks me up is that because I'm not fawning over him, or because I can be objective about what he actually put on the court in limited minutes last year and what he did prior in Summer League I'm suddenly down on him or not admitting to his greatness or admitting to some fault. I'm ecstatic that he's put together the second year that he has, and while there was always the potential (based on his draft position and production in college and high school) there wasn't much actual physical evidence at the NBA level that he was going to transform himself this drastically or this quickly.
FWIW I did start the "Free Bayless" movement and am still the president of that movement (unless a coup occurred without my knowledge?)
http://www.sportstwo.com/forums/showthread.php?t=130729