No Mac 10.8 is not listed in SCL of BE 2012 so yes it is not supported
Please check page number 19 from the SCL
The current supported versions of Mac OSX with Backup Exec 2012 are 10.5.8 , 10.6 and 10.7 (Lion).
Mac OSX Mountain Lion RC is still not available with Apple until now via Software Updates. Support for 10.8 Mac OSX will be conveyed when it is done.
Thanks, before I read the SCL and did not see 10.8 listed. I was reaching out the vast pool of silohed Symantec employees to see if there was any newer information/intel on the "idea" of how soon the support would be in place.
Thank you all for your speedy response!