On paper, the Detroit Lions entered the 2012 season with one of the most talented offenses in the NFL. They weren't able to live up to that billing, though. Injuries and general inconsistency were huge problems for the Lions, and although Calvin Johnson had a record-breaking season in yardage, he wasn't able to get into the end zone quite like he did in 2011.
This year, the Lions once again have a lot of talent on paper, especially after adding Reggie Bush into the mix. Bush decided to join the Lions in part because there is so much talent on the offensive side of the ball, and he doesn't see any reason why they shouldn't be the NFL's top offense in 2013. From the Lions' official site:
"Honestly, I believe there’s no excuse for us not to have the No. 1-ranked offense. We have all the right pieces and the necessary players here to be the top offense in the league. No excuse."
Bush is correct when he says that the right pieces are in place. The Lions have a talented quarterback in Matthew Stafford, an excellent backfield in Bush, Mikel Leshoure and Joique Bell, an elite receiver in Calvin Johnson and talent at tight end in Brandon Pettigrew and Tony Scheffler. There are question marks for sure (offensive line, receivers not named Johnson, etc.), but the Lions have great potential on offense. They just need to be more consistent to actually live up to it this year.