With the recent problems that McAfee customers have had over the last week there has been lots of opinion that not only should the AV vendors have better testing but customers should test AV signatures before deploying.
Is this feasible? If you are doing this already do you take other measures to minimise exposure to malware while you are testing?
Update: With respect to feasible I mean is it feasible to run through a whole gamut of tests for each AV signature/definition update or do you restrict to just critical apps or critical functionality tests? Do you have a different approach for servers compared to desktops?