Those who visit YouTube's website everyday have surely already taken notice of YouTube's new design. With having now a lot of social elements implemented as well as Google+ emphasized, it really has more the look of a social networking website than a video sharing site now.
Looks like Google tries to use all the potential methods available to make people use their social networking site "Google Plus". They really gotta be freaking afraid of Facebook taking Google's #1 position in the internet world soon.
The background is that over the last years, a lot of websites are experiencing more and more traffic from Facebook while traffic from Google is relatively declining. So the result after a couple more years might be that people will start to search the web completly on a social level with having Facebook deliver them the search results their friends have recommended - and not some algorithms from Google.
So based on that quite possible development Google tries to catch up with Facebook. Yeah right Google, good luck with catching up with almost one billion active users. Google is publishing numbers like it has over 60 million users now, but it's like the most of the people have just joined Google Plus out of curiosity and not in order to use it like they do it with Facebook.
When Google is thinking that they will be able to catch up with Facebook in its social capabilities, then it's like when Microsoft is saying that Bing will become much more popular than Google's search soon. Don't get me wrong Google, I like you and your services, even Google Plus - it's ok and in some ways really useful especially for my business contacts, but in my opinion it isn't even close to become what Facebook is already since several years - a part of our modern culture.
Facebook was made popular by teenagers and college students - young people. They have brought it to their parents, their elder brothers and sisters and everybody else. It wont work the other way round. It's not a coincidence that over 80% of Google Plus users are grown up male dudes - it's basically like Chatroulette except that here everybody seems to keep his pants on.