Antivirus and SQL -- "to do or not todo"?

I was reading through  http://support.microsoft.com/kb/309422/en-us

and plan to adopt its suggestions NOT to AV scan certain file SQL (2008) file extensions:

>>>>>>>>>

mdf, ldf, ndf

.bak, .trn

.sql

 Full Text Catalogs

>>>>>>>>>>

Per the URL "we strongly recommend that you individually assess the security risk for each computer...." I suspect the risk is generally small and, from a performance, perspective prefer not to AV scan them (realtime or otherwise) on any of our sql servers.  What are your thoughts on this?

TIA,

edm2