But because Microsoft has made the browser inextricably integrated with Windows, any upgrades will likely have to be delivered through a service pack update to the operating system, which is something Microsoft said probably won't happen. The company is looking at whether service packs might be viable, sources said.More info at eWeek
Microsoft aiming to regain marketshare from Firefox

Microsoft recently hold a secret webcast in which it discussed several potential fixes to Internet Explorer in order go regain market share it lost to other browsers - such as Firefox.