At risk of starting a flamewar, I'm starting to like Microsoft more and more these days. They have a 100% predictable support lifecycle and don't pull the rug out from under people with virtually no notice.
We've literally just got rid of our IE6 support a couple of months back and have IE8 as minimum spec (IE7 is irrelevant as any platform that can run it can take IE8). I doubt we'll see the end of IE8 for a few years which is not a problem for us.