The word seems to be that the Eagles wanted to get a new deal for Garcia done before the start of free agency. Garcia had reportedly asked for a 5 day grace period from the start of free agency presumably to see if he could find a starting job. The Eagles weren't willing to get into a bidding war with anyone and just turned around and extended Feeley.
I'm actually very happy with this move. Eagles fans will never forget the job Garcia did taking over for McNabb turning the season around, winning in Dallas on Christmas, winning the division title, and beating the Giants in the first round of the playoffs. That said, he's 37 and Feeley is a younger and more than capable backup. Even knowing what Jeff had done here last year and even if he came back for the vet minimum, I think I'd still prefer Feeley in the backup role. It just makes more sense for the next several years.