We have it installed and set to bypass the usual extensions and haven't had any issues. Hopefully there won't be an exploit that use .MDF extensions to sneak by AV, it's probably a matter of time.

Along a similar subject, I'd be curious to hear what other's policies are on server monitoring for SQL boxen; we have standardized on IBM Director and I have banned it on SQL servers due to many problems I've seen with resource consumption, unplanned reboots, etc. It's a little invasive to say the least. Do any others use Director for monitoring SQL hardware? Any stories to share?