Here's what no one's saying about Blockbuster's acquisition of Movielink, the Hollywood-backed movie-download site: It's a desperate move to shore up Blockbuster's online failures. Blockbuster, remember, has been promising video downloads for most of this decade. First came a deal with Enron's broadband division, and, well, we all know what happened there. Since then, Blockbuster has said that video downloads would be coming soon for years. But Hollywood studios, burned by past negotiations with Blockbuster for sharing video rental fees, are understandably loath to cut favorable online deals with the video-rental chain. And it's hard for Blockbuster to compete technologically with the likes of Apple, Amazon.com, and Netflix. Buying Movielink gets Blockbuster deals with studios and ready-made tech — all of which gives it merely a place at the online-video table, not the ability to eat everyone else's lunch.