Sage signed a two year deal, he's got one year left, and no way Houston lets him go for anything less than a 2nd round pick. He's too important, given Shaub's fragility.
I think Seneca signed a 3 year deal at the beginning of last year, so he's probably out too, though Seattle picked up Charlie Frye from Cleveland last year, in exchange for a 6th round pick.
The Vikings will definitely pick up a veteran QB this off-season, they can't go with crappy unproven players in the 2 and 3 deep at the most important offensive position. My guess is that they'll take a flyer on a QB in the sixth or seventh round, like Brad Johnson was selected 14 years ago.
The Vikings big boneheaded move was not protecting Tyler Thigpen, and allowing him to go to KC. He sure looked like the perfect #3 quarterback, young and raw, but potential.
My guess? Vikings pick up Brad Pennington sometime in the next four months.