On the heels of big redesigns at rival portals Yahoo (NSDQ: YHOO) and AOL (NYSE: TWX), Microsoft (NSDQ: MSFT) is unveiling what it is calling the most significant overhaul of MSN.com in more than a decade. The home page’s iconic blue background and long lists of links are being replaced with an airy, news-site style design that puts a sharp emphasis on six key verticals: news, entertainment, finance, lifestyle and local (Click on photo to the left for a gallery of screenshots). U.S. executive producer Scott Moore tells us that the goal is to get the site’s 100 million monthly visitors to come more often. Attracting new users is a secondary goal, he says. While traffic us up over the last year and Microsoft sites have surpassed Yahoo sites in popularity in recent months, Moore says that users often said MSN.com was cluttered and outdated. In an interview with paidContent this spring, MSN Corporate VP Erik Jorgensen hinted at many of the changes, saying that the site needed “a new look and feel.”