If Steve Young is in the hall (he is), I see a clear path for Rodgers to be. He's a very, very comparable player and has accomplished similar things in his career up until this point and both backed up a different HOF QB for a number of years before they started. If he plays a few more years at the same level or wins another SB he is a lock for sure. Rodgers is in his 8th season as a starter, Young made it in after starting 8 mostly full seasons for SF (1 for TB, and a 9th he started but was injured and forced to retire)
So far Rodgers:
Has won a superbowl
Superbowl MVP
NFL MVP
Highest career passer rating in regular season with a minimum of 1,500 passing attempts (106.4)
Only quarterback in history to have a career passer rating of over 100.0
Only quarterback in history to have a career passer rating of over 100.0 in both the regular season and postseason.
Best touchdown to interception ratio in NFL history (3.93)
Lowest interception percentage (1.6%)
Best passer rating in a season (122.5, 2011)
Even if he retired after this year, he would have a good shot at the HOF, though I think its a bit early to say he's a lock to make it. He probably will never get close to many of Favre/Peyton's records due to starting a few years late, but everything he has accomplished to this point basically say he is the most efficient QB of all time.