On the Mac, IE is most definitely not the most popular browser out there. IE for Mac and IE for Windows are completely different creatures, which share only a name and an icon, and nothing else. Dump IE for Mac and support Mac browser that are actually updated, like Safari and Firefox.
IE is the bane of my life; one of the companies which provides database software to us insists that we use IE for Mac – foolish, uninformed and completely ridiculous to not support something else, but our users comply. That’s fine for that particular database app, but I’m actively investigating ways to prevent IE for Mac from exiting our intranet, to force users to use something newer.