Kaido Järvemets, a fellow ConfigMgr MVP, has a cool new powershell script.
With it you can set the User-Device affinty.
http://depsharee.blogspot.com/2012/04/create-user-device-affinity-with.html
This is a necessity with the new ConfigMgr 2012 product where User Affinity is a key aspect and needs to be understood and user. Check out his blog above.