I went to 1 job fair back in September 2012 in ATL. Never did a Meet and Greet, but was working on trying to get one when I got the call for the interview.
Its probably helpful to some who might not otherwise get picked from the awarding of points by the system but who knows. I had 11 letters of rec, 6 were from CAL/UAL people, the others were from other sources.
I am currently a regional CA, Check Airman, and APD, so the points I might not have gotten from a M&G probably came from the other stuff.
I'm not a big fan of the job fair thing, and I'll never know if its what got me the call or not, but do whatever it takes to get the job you want (within reason of course).
Looking forward to starting class soon.

Good luck!!!