Three lessons from a weekend where Tim Tebow became mortal and the Legion of the Overrated gained a couple more members.1. There are only three legit national title contenders. If the first real weekend of conference play taught us anything, it's that Alabama, Florida and Texas are the only real theats to win the BCS crown. Of course, it may not play out that way. An injury or two (see Tebow's concussion or Brandon Spikes' Achilles) could level someone's chances and open the d...