Generation Y @ work... less loyal, but that's the employers' fault?

I can't understand why McKinsey made the video interview beneath so short, but it's still a worthwhile introduction to a hot subject: how does Generation Y look at their professional environment? Are they less 'loyal' to their employers? What can employer do to retain young talent when it's so easy for them to look and find the next big opportunity?

If you have some datapoints on the subject please leave a note beneath...

(From McKinsey Quarterly:) Clay Shirky, author and professor of new media at New York University, has written at length about Twitter’s and Facebook’s influence on politics and economics, even before the social-media tools played a key role in the popular movements sweeping across the Middle East.
These technologies also shape behavior at the office, especially for younger employees who log into Facebook at work, e-mail from their BlackBerry on weekends, and consider their career paths pliable and open-ended.

In this interview, conducted at this year’s World Economic Forum, in Davos, Switzerland, Shirky sits down with McKinsey’s director of publishing, Rik Kirkland, to explain the opportunities and constraints that net generation employees balance at work, as well as how managers can do a better job of understanding and retaining them.