So based on your YouTube activity, things you've favorited, etc. you'll get all your recommendations on your new personal homepage. The editors picks have worked well on the regular YouTube homepage, so I'm sure these personalized recommendations custom tailored for each user will fare well, too. And as most of you subscribe to other users in order to be kept abreast of their new content, the updates for these subscriptions won't be too far from what you already had on YouTube.
Nor are we the least bit surprised that the new personalized homepage boasts friend activity, too. I know there isn't a whole lot of actual networking going down at YouTube, aside from the long strings of comments some videos can amass, but the friend activity "feed" will let you know when you've got pending friend requests, when they've uploaded a new clip, and what activity is occurring around various video clips (ratings, comments, etc.).