I don't even know if the desktop client has this, but a feature I'd really enjoy is the ability to see full reviews of other users, rather than just star ratings. "I really loved this movie, but felt it was a bit long." or "This movie was terrible, but visually stunning!" are the sorts of things I'd like to know about why someone rated it what they did. Will give me a better idea of if I'd like to add a movie to my collection.

It would really help make this app an all in one solution when at the video store.