At least according to People Who Know Things on the Twitter machine. First reported by Mark Berman, Schaub's extension is apparently for 4 years worth $62 million, with $24.750 guaranteed. This will keep him under contract through the 2016 season, when he'll be 35 years old with the hairline of someone twice that age.
Update: (via Berman, h/t to Big T33) Texans converted portion of Johnathan Joseph’s salary into signing bonus to help clear $4 million in cap space to sign Matt Schaub.
No details available on Tim Jamison's extension as of this writing, but we'll update as information comes available.