When the Virus definitions of 2010 and 2011 will be Integrated?

Dear administrator:

          Just now I enter the offlline virus definitions site(http://www.symantec.com/avcenter/download/pages/CS-N95.html), I notice that the definitions of 2010 and 2011 are different, so I am puzzled, why they can not be Integrated and when they will be Integrated ?

          By the way,  someone told me that SONAR3 is inferior than SONAR2, is this true?

       Cheers 

  jianrenyouxi