* the ability to rate videos from one star to five stars
* add comments / video reviews
* add tags for the videos (Google likes to call them labels)
Some snippets of code:
// sends a review (if review is defined) and receives a list of current reviews
function updateReviews(url, docId, sortByRating, loc, reviewer, review)
// called when submit review is clicked
function publishComment(url, docId, loc, name, review)
// sends a tag (if name is defined) and receives a list of current tags
function updateTags(url, docId, name)
function setStars(url, docId, val, location)
So Google Video really tries to catch up with YouTube and will add the missing features.
Update: the new features are live. You can search the videos using the label operator, for example label:funny.