Word is that the official 2009-10 Elias Rankings are out, so we will try to get a hold of those soon. We've got Eddie Bajek's reverse-engineered rankings available here in the meantime.
For those interested in seeing how the sausage is made, Eddie has provided a look into the American League catchers group. As explained here, the stats used for catchers are plate appearances, batting average, on-base percentage, home runs, runs batted in, fielding percentage, and assists. An adjustment is made for days spent on the disabled list.
The catcher breakdown can be seen here or directly below.