Obviously this is terrible news, and continues a particularly disturbing trend amongst Jays pitchers. In the last two-ish years:
Gustavo Chacin had elbow problems and missed much of 2006 and 2007,
B.J. Ryan has had TJ surgery and missed a year,
Brandon League missed essentially the entire 2007 season with a strength training injury,
Casey Janssen had surgery for a torn labrum and missed a year,
Dustin McGowan missed half a season with a labrum injury,
Jeremy Accardo missed much of this season with a forearm injury.
I don't know if this a particularly bad record, though I suspect it is, but the Jays have now lost three starting pitchers and four good relievers to serious (3 month+) injuries in essentially the last two seasons. Good grief.
Right now the candidates to start in the rotation next year are basically Roy Halladay, Jesse Litsch, and David Purcey, and then theoretically some combination of Dustin McGowan, Casey Janssen, AJ Burnett, Scott Downs, John Parrish, Scott Richmond, Ricky Romero and Brett Cecil. After AJ Burnett that list doesn't really inspire much confidence though.