After the season the Elias Sports Bureau will take all players over the 2009-10 period, divide them into five groups for each league, and rank them based on various statistics. Then each player will be labeled a Type A, B, or none.
Eddie Bajek has reverse-engineered the Elias rankings, and he's providing that information exclusively at MLB Trade Rumors. Here's a look at how the players rank for the period beginning with the 2009 season running through June 9th, 2010. The Google spreadsheet below has separate tabs for each position group. The players have about four more months to change these rankings.