[MIX06] How long will IE6 be supported? How about IE5.5?
At Mix06, Andy Clarke asked if IE7 could be be released as a critical update, and support for IE6 dropped soon after IE7 is released.
The answer is that Microsoft has a policy of supporting software shipped with an operating system as long as the operating system is in service. Since IE6 shipped with Windows XP, IE6 will be supported as long as Windows XP which will probably be a few years after Vista is released.
IE5.0 shipped with Windows 2000, so I'm assuming that it will leave mainstream support along with Windows 2000 on June 30th (thanks for the correction, Jeff). It looks like IE5.0 may be supported longer than IE5.5, which is rather odd.