On strategic risk assessments not testing the anti-virus signatures before being deployed should be considered a vulnerability.  Many of my customers believe this is ridiculous and not practical, however I report it anyway.   Whatever the case, the organization has the decision to accept the risk, as I am only there to point it out.  There is a great example published where a routine update caused serious problems forcing customers to have to re-install the operating system.

 http://news.yahoo.com/s/zd/20071206/tc_zd/221141;_ylt=AhIN_X.SMrgYGlzdK7zmNe8E1vAI

So you decide.  Should Anti-virus software be tested before deployment.