Last season there were thirteen quarterbacks who threw for 20 or more touchdowns.  I use 20 passing TDs as a milestone when projecting fantasy QBs at the beginning of the season because I've found it's a fairly reliable year-to-year marker.  If a QB reaches 20 passing TDs in one season, he's very likely to reach it the following season as long as he plays (at least) the same number of games.  I consider QBs with 20+ pass TDs to be solid fantasy options.
 
While there's still a quarter of the season left, here's a review of those thirteen QBs and how they're doing this season.
 
Quarterbacks Already At 20+ TDs
- Drew Brees
- Kurt Warner
- Philip Rivers
- Jay Cutler
- Tony Romo
- Brett Favre
 
Out of the 13 quarterbacks, nearly half of them ALREADY have 20+ touchdowns and the season is only 75% finished.  Special notice goes to Tony Romo, who reached 20 despite missing three games with an injury.  Having any of these guys on your team has been well worth it.
 
Quarterbacks Who Won't Reach 20+ TDs
- Tom Brady (Injury)
- Derek Anderson (Benching/Injury)
- Matt Hasselbeck (Injury)
- Carson Palmer (Injury)
 
Another 30% of the QBs will fail to reach the 20+ milestone, all of them due to injury.  Although, Derek Anderson's injury masks the fact that he plain stunk this year.  Still, you can't predict injury so you can't do anything about that.
 
Quarterbacks Who May Reach 20+ TDs
- Peyton Manning (19 TDs)
- Eli Manning  (19 TDs)
- Ben Roethlisberger (13 TDs)
 
Unless the Manning Family Estate is attacked by zombies one night (it's possible, have you seen Archie lately?) the Manning brothers will both top 20 pass TDs once again.  Roethlisberger is a tougher call; he would need two pass TDs per game against Dallas, Baltimore, Tennessee and Cleveland.  That seems unlikely.
 
So out of the thirteen QBs I targeted based on the 20+ pass TD milestone, 8 of them (62%) have reached that milestone already or soon will.  Another 3 of them (23%) were busts due to injury and the final two QBs (Anderson and Roethlisberger) just didn't repeat.  That's a pretty good year-to-year guide.
 
By the way, there are another five QBs who have or will soon pass 20+ TDs this year.  Interestingly, all of them -- Rodgers (20), Cassel (13), Orton (13), Ryan (13), and Thigpen (13) -- are new starters.  There isn't a veteran arm anywhere near 20+ TDs that wasn't there last season.  Remember the preseason hype for guys like Delhomme, Campbell and Garrard?   Nope.  There won't be any veteran breakouts this season.