Will Magic Bullet 1.5 work on AE 6.5?

Short and to the point: Yes.
There's an update (thats free) on their site for AE6.5: http://www.redgiantsoftware.com/magicbulletupgrade.html

mine works but you need a powerfull pc and lots of ram cause it is heavy stuff. And save your work cause sometimes they funk up adobe after effects 6.5 .