Even if he were healthy, he is playing on a team that needs to be run oriented. If we assumed the health of all QBs (including Favre), for fantasy purposes I would have him in the third tier of QBs (or a #2 in a 10 team league). Assuming health, I think he would be higher then that for real life purposes (able to lead a team, etc).
In no particular order, the tiers I have for fantasy at this point are
Drew Brees, NO
Peyton Manning, IND
Tom Brady, NE
Aaron Rodgers, GB
Kurt Warner, ARI
Philip Rivers, SD
Tony Romo, DAL
Matt Schaub, HOU
Carson Palmer, CIN
Donovan McNabb, PHI
Jay Cutler, CHI
Matt Ryan, ATL
Ben Roethlisberger, PIT
Eli Manning, NYG
Matt Hasselbeck, SEA
Brett Favre, MIN
Matt Cassel, KC
Jake Delhomme, CAR
David Garrard, JAX
Trent Edwards, BUF
Kyle Orton, DEN
Chad Pennington, MIA
Marc Bulger, STL
Jason Campbell, WAS
Kerry Collins, TEN
Shaun Hill, SF
Joe Flacco, BAL
JaMarcus Russell, OAK
Brady Quinn, CLE