Personally, I'd like Ajax for the Comments, so that if you're watching a movie and want to comment, it doesn't reload the page. Sort of like the shoutbox.
The add New video link I wish was an icon so than it'd be easier. For the Other options, maybe put a drop down icon that says Other options or something?
When making a category, I don't always need a description, so if I don't fill one in, it allows me to create it.
Also, if you go into a category and than hit the add video link, would it be possible for it to automatically select that category?
For example:
I'm in Category A, and I hit New Video. It automatically selects category A for the category the video is in.
And Sub Categories