If a bunch of my friends have seen / liked a video or a channel, I should be asked to evaluate it. Probably blocked because the opt-in flow for friends isn't fun.
Sharing
I'd like to have an easy way to share a feed of "liked" or "shared" videos as a blog, not as individual sharing actions. In the current setup you can share individual videos but not channels, and not in a repeatable way (as rss would be, for example)
Automatic intro skipping
Detect those animated 1-5s long intros that people put, even on short videos, and automatically skip them. They rarely have sound, which can help skipping them.