I originally submitted an application through my university's career page. I got a follow-up e-mail from the campus recruiter, as well as another recruiter, asking me to attend the info session and sign up for an interview. The info session wasn't very detailed about the actual rotational program, but they really emphasized the culture at LinkedIn, and how they're really out to change the world.
I had my interview the next morning, and it was a fairly standard behavioral interview. It's definitely more chatty than formal. He seemed primarily interested in my consulting background, and how well I could integrate myself into the LinkedIn atmosphere. They really, really care about cultural fit.