Twitter has unveiled a major revamp of its home page, featuring a split screen with far richer multimedia content and contextual connectivity to other users. Observers say the move brings Twitter.com a little closer to Facebook and could spell disaster for third-party client developers. It’s also an attempt to make the platform friendlier to advertisers and to create on-screen real estate for promotional content, experts say. “The redesign is as much for advertisers as it is for users, as it will give new visibility for sponsored tweets and trends, as well as content disseminated by marketers,” notes Irina Slutsky.