OK, I was at the dealership regarding my gas gauge issue (see previous reply in different thread). I was hoping that the fix for the 2005 gas gauge would work on the 2006, or they have a similar fix.

No luck on that issue, but came across some useful information for 2006 Cobalt SS 2.4L PCMs.

They checked my PCM code against the most current revisions from GM and found out that my PCM came from the factory up to date.

Here are the current revision numbers:
#1 12605331 new software to correct case learn issue at assembly plant
#2 12605696 new calibration for start of production
#3 12605693 new calibration for start of production
#4 12605698 new calibration for start of production
#5 12605546 new calibration for start of production
#6 12605544 new calibration for start of production
#7 12600036 new calibration to correct problem occuring at the assembly plant. does not address any service issues.
#8 12605694 new calibration for start of production

I hope this information helps, these should be the most current revisions of the PCM for the 2006 model year