The ability for users to choose the MVP of the episode is one of my favorite additions to TV.com, but I think we need to find a way to expand it to more than just six people.
Most TV shows have more than six stars nowadays, and there are certain episodes where the guest stars really do steal the show. Also with reality shows, like Survivor, American Idol etc. you're going to severely limit choices when you have judges, hosts and all the contestants.
Guest stars might require more work in programming, but I think at least modifying it so you can choose from all the stars would be feasible.