After months of leaks, Yahoo finally unveiled its new homepage today and though it may not look that different, its new personalized news feed is the most important, and potentially most lucrative, part of the new look. Much like the rumored versions from a few months back, the new page takes the look of old Yahoo and modernizes it, spreading it out across the entire screen, as you can see in the screenshots below via MSNBC's Rosa Golijan, with new on the left and old on the right:  

The most important part, however, is that stream below the big news stories, which Yahoo has turned into a customizable, personalizable social news feed. The page not only allows people to customize certain topics they would like to read, but relies on an algorithm to choose stories that friends liked. People now get a lot of their news from friends on Facebook and Twitter, so why not make Yahoo like that, too. But beyond keeping up with the social news trends, the social feed will also allow the site to sell better ads, as Yahoo VP of Product Mike Kerns explained to Wired's Mat Honan. The newsfeed will also host personalized text and video based ads, all based on your tastes. "The personalization and recommendation system will have very similar targeting capabilities with advertising," said Kerns. 

Much like Facebook has "sponsored posts" within its news feed, Yahoo too will insert recommended content within the stream, Yahoo's design director Jackie Goldberg added. "We will have clear attribution to make sure users don’t confuse it with a recommended piece of content." As far as advertisers are concerned, the more personalized an ad the better. But, it also gives Yahoo  an advantage in its stated area of interest: Mobile. Like every other tech company these days, Yahoo CEO Marissa Mayer has a vested interest in following user eye-balls to cell phones. By sticking personalized ads right in the news stream, Yahoo makes the transition from Web to phone ads easy for advertisers. The promoted content will still show up on a tiny little screen, right in the news stream. 

Other than that, the page looks very similar to old Yahoo, which is kind of the point. You can watch Mayer talk about how much she loves the personalized feed on her appearance on this morning's Today show. "It's more personalized and it's more dynamic," she says. Though she doesn't mention the ad potential, that's probably why she loves it so much. (She also talks about life as a mom, because no Mayer interview can be conducted without asking about the world's most important baby.)