I'm not discounting the vaccination process entirely but I think there are too many people in the Autism "community" pinning there hopes to find something, anything, to blame.
What is really bothering me about this blame game is that things are purposely being confused. If you will notice in many of these posts, both MMR and thimerosal are being used interchangably as a cause of autism.
But it won't work. The anecdotal evidence uses the introduction of MMR in the US to correspond to the alleged jump in autism cases. But now we are told thimerosal is to blame, but since it has been around much longer than MMR, the people making these allegations are forced to explain why we only see autism cases jump in the 80s.
Essentially it seems to me that they are just throwing a bunch of allegations up against the wall to see what sticks, much like breast implants.