The site is intended to feature music videos, artist-related content and interviews. The aim of course is to bring in more high profile brands who arent necessarily interested in advertising on YouTube because of its user-generated content.
It has been mentioned by CNET that the three other major labels have all been approached to join the Vevo service. Im sure this would all work in the same way as Myspace Music in which the major labels all have an equity stake. Myspace Music has amazed me that so many independent labels have come on board with the solution, because they should realise that part of their profits are still going to the major labels. However, with Myspace Music most independent labels need to have their music on the site, so why not make some revenues in the process.