My friend Jamie Cardoso just published an article in CGSociety regarding Mental Ray in Max 2011. Check it out

http://features.cgsociety.org/story_custom.php?story_id=5655&page=1

You can also find a bit more behind the scene on his blog

http://jamiecardoso-mentalray.blogspot.com/

Related posts:
Jamie in 3d World
Mental Ray for visualisation 2nd edition