Google moved from the TV shows to the user submitted videos, but never forgot the captions. Google Video lets you add captions for your videos, but the big news is that soon you'll be able to search inside a video that has captions. That's especially useful for long videos. Instead of losing an hour watching the entire video, you'll be able to find the relevant scenes.
Another new feature will be video alerts.
Related:
10 Google Video tips
What's next for Google Video?