The research won't stand up to any hardcore statistical analysis, but it's a good read about all the pitchers looking to make comebacks in 2009. A quote about looking at past seasons:

"Of the 29 candidates, only 4 bounced back successfully the next year. A 5th pitcher bounced back in 2 years. [L]ooking at the five successes, what do they have in common?

1. Pitched in September/October of ‘down’ year - 4 of the 5 (Randy Johnson excluded) pitched in the prior September with three of them (Schilling, Escobar, Greinke) pitching in relief. A positive sign that they had gotten through most of their rehab (mental in Greinke’s case) and could be ready by the beginning of the following season. Only 11 of the 24 who failed in their comeback pitched in September/October.

2. Non-Arm Injuries - 3 of the 5 (Escobar and Duke excluded) had non-arm/oblique injuries - Schilling (ankle), Randy Johnson (back), Zack Greinke (mental). Only 2 of the 24 failures had non-arm injuries (John Thomson - finger, David Wells - knee).

Good 2009 bets, at least to some degree, according to the article: Adam Wainright, Anibel Sanchez, Chien-Ming Wang, Chris Young, Erik Bedard, Francisco Liriano, Josh Johnson, Kelvim Escobar, Tom Gorzelanny.