I like the mandatory star rankings; I really do. Even if you can't be bothered to fill out a full opinion, it forces you to give some kind of feedback. It's a very good idea, and implemented well.
However...
It might be a good idea to add a "null" or "decline to rank" option. For example, if someone downloads a video but can't watch it for whatever reason, it's unfair to both the downloader and the creator if the downloader is forced to provide a ranking sight unseen.
The drawback to this is that I can't come up with a way to prevent its abuse, and you would also have to add the ability to actually rank the video later on.
What do you think?
