Thoughts on Luis Exposito?

I was reading the Red Sox top 15 prospects list that just moved this morning on www.baseballhandyman.com (kudos to my boy mike newman for putting together such a solid site). One guy, I kept coming back to was catcher Luis Exposito. He was a 20-year-old last season who had stints in Lancaster (A+), which I understand is a hitter's park, and Greenville (A-). He's big and projects to hit for power (20+ HRs a year when he reaches the majors). Because he plays good defense, he likely won't be moved off catcher. He's hit for a high BA almost everywhere he's been though his poor plate discipline (doesn't know how to take a walk) affects his OBP.

Baseball America and all of Red Sox nation say he'll be Boston's starter at catcher by 2012.

So my questions to you are:

1. Does this guy project to be an above-average MLB catcher?

2. Is he fantasy-worthy?

3. Should I sign him now or take a wait-and-see approach? I'm absolutely stacked at catcher (McCann, Salome, Skipworth, Lucroy, D'Arnaud)

Your help would be appreciated. Thanks.