Can't say what percent of the time he would be the #1 read, but not sure that matters as much. Finley appeared to be the #2 read on the vast majority of plays before the injury. He has that Gates-like freakishness to be at least semi-open on practically any play. Whether this is because of skill or sheer physical size, the fact remains that when Rodgers couldn't find his primary target, he just threw to Finley. By the third game of the season, it looked almost automatic: "Whoops, Jennings is in double coverage, let me toss it to the TE". Maybe that changes this season, but I doubt it - I think Finley averages 5+ receptions per game if he stays healthy.
Finley played in four games in 2010 and the following provides the targets for each person in the first four Packer games:
1) Jennings 10-5-6-5-26 total
2) Driver 7-5-11-3-26 total
3) Finlay 6-6-9-5-26 total
4) Jms Jones 3-7-5-1-16 total
5) Nelson 2-2-4-1-9 total
6) Br Jackson 2-1-4-1-8 total
Equal split between the top three targets, I guess it just seemed like Rodgers was ALWAYS going to Finley. However, I am sure that this will all change going forward and Finley grabs the lion's share of targets for the Packers.