Since this is a short week and Drew Stanton suffered a concussion during yesterday's game, there is no way that he will be ready to play on Thursday against the Titans. Because the Lions don't want to have only one healthy quarterback on the team, Drew Henson was signed to the active roster today and will be Daunte Culpepper's backup.
According to John Niyo, the deal is two-years long, so I'm inclined to believe that Dan Orlovsky will be headed to the injured reserve to make room for Henson. If Henson was simply going to be on the active roster until Stanton was healthy again, there would be no reason to sign him for two years. Since the Lions did just that, my guess is that they want to keep him on the team for at least the rest of this season and are keeping him in their future plans.
The Lions also re-signed wide receiver Eric Fowler to the practice squad and released Joel Filani, another WR, from it.