Hey sfd,
"AA is the tougher league to hit in so he won't be seeing much improved pitching in AAA, he will probably go from AA to the bigs IMO"
I think he'll stay in Richmond for the remainder of the MiLB season, then get a call-up in September.
Then, next Spring, he'll get a Spring Training invite and compete for a job with the big club, although he'll likely start 2013 in Fresno. He's only got around 1,050 MiLB ABs at present, so he'll probably end up with about 1,100 by the end of the regular season.
My guess is a mid-2013 call-up at the earliest. A couple hundred AAA ABs ought to make the Giants a lot more comfortable with the idea of bringing him up.
LoneStar