Mobile World Congress is only a few days away and the rumors have been flying about Windows Phone 7 updates. The latest rumor comes from Mary Jo Foley at Zdnet, who says her sources are talking about Internet Explorer Mobile 9 coming to WP7. Although the first Window Phone 7 update has already seen a delay, with the first update dubbed "NoDo", now slated for March 8, the next major update is already building an interesting feature list. According to the sources, the "Mango" update will be hitting the market this holiday 2011 season, and will feature Internet Explorer Mobile 9. Currently, Windows Phone users are using IE Mobile, or better known as IE 7 Mobile, with some IE 8 featured added into it. If these sources are correct, Microsoft plans on skipping IE 8 mobile entirely and release a mobile IE 9 HTML5-compliant browser and multi-tasking for third party apps with the "Mango" update. Earlier today, Microsoft released Internet Explorer 9 RC for Windows PCs. The latest release of IE 9 brings a lot of UI and performance improvements with a number of new features, including ActiveX filtering, quicker tab closing, and much more. The latest HTML5-compliant scored a total of 95/100 on the Acid 3 test.