What happened to YouTube Friends?

As of December 2011, we have merged Friends with Subscriptions.

Please read below for a more in-depth understanding of how to manage your subscriptions, including, how to subscribe to your YouTube Friend's Channels in order to stay updated on their activity. By not subscribing to your YouTube friends, those friends will become Contacts in your Address book and will retain previous friend-like functionality such as messaging.

support.google.com/youtube/bin/answer.py?hl=en&answer=57958