Timeline for Bills' QB decision

Every NFL team would like to have a true franchise QB behind center, but the reality of the situation is that there simply aren't that many franchise QBs walking Planet Earth right now. In an effort to give themselves more options in the quest to find their next Jim Kelly, the Buffalo Bills drafted EJ Manuel in the first round this offseason and also secured journeyman Kevin Kolb. There hasn't been much chance for either man to separate himself as the No. 1 QB yet, so when should we expect a decision?