Brad Lidge is not anywhere near the pitcher he used to be. That being said, he could still be a solid contributor for the Nationals in 2012.
First of all, Lidge's average velocity on his fastball and slider have gone down significantly over the last two seasons (where he has missed significant time due to an elbow injury and rotator cuff surgery). Last season, his fastball velocity averaged 89 MPH and his slider averaged 80.9 MPH, far off of his career paces of 94.6 and 85.8 respectively (and his 2010 post-elbow injury 91.7 MPH average fastball and 83.4 MPH average slider). He also leaned on his slider much more in 2011 than ever before, throwing the pitch 72% of the time as opposed to about 45% of the time over his career and 60% of the time in his previous career high in 2011.
What does this mean? It's hard to say. Eno Sarris of FanGraphs theorized in July that if Lidge could dominate with his slider, he could continue being a reliable reliever in 2011 and beyond. His 2011 rate stats were both good and bad, with a 10.71 K/9 rate but a 6.05 BB/9 rate to go along with it. The high strikeout rate gives me optimism, as anything over 9 is very good and over 10 is awesome. The walk rate doesn't worry me all that much because, even though Lidge has never been a wizard with his control, he's still generally in the 4-5 BB/9 range, not near 6.
Bill James' projections put Lidge down for a 3.86 ERA, 11.57 K/9 and 5.14 BB/9 in 2012 with a 1.03 HR/9 rate. I'd be surprised if they ended up around there, to be honest. I think he's going to be either awful or solid. If he can get solid velocity out of his fastball and slider and control him, he'll be pretty good; if he can't, he'll probably be pretty bad.
Side note - I hope you enjoy 2011 Nationals Draft Info. I'm in the process of updating the profile for each signed player with 2011 stats (tables from Baseball-Reference) as well as new analysis and reports from the likes of Luke Erickson of Nationals Prospects, Ryan Sullivan of Nationals GM, Todd Boss of Nationals Arm Race, Jeff Reese of Bullpen Banter and potentially some other surprise guests. I'll be updating them three times a week (Monday, Wednesday and Friday) with some double posting possible.
To date, the following players have been updated:
Monday, 1/23: 50th round OF Anthony Nix
Wednesday, 1/25: 45th round RHP Richie Mirowski
Friday, 1/27: 41st round IF Bryce Ortega
Monday, 1/30: 36th round LHP Ben Hawkins
Thursday, 2/2: 35th round RHP Alex Kreis
Friday, 2/3: 33rd round 2B Trey Karlen
Monday, 2/6: 32nd round OF Billy Burns