For a car site I run I get the following IE usage over the last couple of years (monthly visits in the 5K range):

apr 2007 71.8% oct 2007 74.5% apr 2008 72.0% oct 2008 67.1% apr 2009 67.6% oct 2009 65.6% apr 2010 58.5% oct 2010 61.2%

That's still a considerable majority of IE users.