I'd love to see a link to IDC's numbers and what methods they used to gather them since they apparently contradict nearly every other metric out there.

The numbers gathered are for total traffic, most web sites have no idea whether the end-point is a business user or a consumer. There are a lot of businesses that are slaved to IE in some way shape or form due to applications requirements (usually for internal apps), that doesn't mean people use IE to surf the web using IE.

Years ago Microsoft recognized the strategic importance of the internet, it's the entire reason Microsoft made such huge efforts to crush Netscape. It's also why they spent 6.2 Billion investing in aQuantive and have spent billions trying to build up Bing, MSNBC, and their other web properties.

The browser is an essential piece of the internet equation, companies use browsers to gather information about their users, Google uses it to steer people to their site, Firefox uses their browser to generate revenue. Whether you are concerned about browser market share or not, there are people in Redmond who are quite concerned with it.