By now you have probably heard that Microsoft will no longer support or develop Internet Explorer for Mac OS. According to a notice on Mactopia:
IMPORTANT INFORMATION FOR MICROSOFT INTERNET EXPLORER FOR MAC USERS
In June 2003, the Microsoft Macintosh Business Unit announced that Internet Explorer for Mac would undergo no further development, and support would cease in 2005. In accordance with published support lifecycle policies, Microsoft will end support for Internet Explorer for Mac on December 31st, 2005, and will provide no further security or performance updates.
Additionally, as of January 31st, 2006, Internet Explorer for the Mac will no longer be available for download from Mactopia. It is recommended that Macintosh users migrate to more recent web browsing technologies such as Apple’s Safari.
I am not so sure this is even an issue that affects many Mac users. The version of Internet Explorer that is available for Mac OS X is antiquated and just plain ugly. I used IE on my old PC mainly to view sites that gave me hassles in Firefox but since my move to a Mac, I think I have opened IE for Mac twice and even then I probably used it for about 10 seconds. The fact is, this version is not even close to Firefox or Safari (or even Camino and Opera).