The goal of drafting Buster Posey, was that he would become part of the Gigantes future as a star hitter who oozed talent and would mean a #3 hitter that could be written into their line up ever day for the next decade.
While we all hope for the best, smart people also prepare for the worst. I'm not that intelligent, so I say we project something in between.
I'm envisioning The Notorious GBP (you like that don't you..) being a very good hitter. To use the catcher analogy, we could say a Russel Martin with more speed, less pop, and greater positional flexibility. If his catching issues (passed balls, calling games, etc.) become duanting, I'd think a position change (2B? I also heard he plays CF) would probably be in order and he would remain a back up catcher. The silver lining to this cloud might be that any team that has the Notorious GBP on it, probably could go another bench player deep on the roster as B-Pizzle (not sure if that works the same way) could be the end of your bull pen. A team that could carry 14 hitters (yes even Giant hitters) would probably do better in close games, especially the later innings.
So those are my thoughts. On a more personal note, I've yet to meet anyone more useless than HR people or career counselers. How in the name of Bill Switft's 1993 season, does one become one of these useless sacks of mung? Better yet, how can you do this in a city/county government job?