Do you think they'll really drop IE8 once IE10 is released next year? Firefox 5 will be released tomorrow. FF 3.6 support will be discontinued? Actually, it would be great if Google could nudge everyone to keep upgrading.
If you think that's bad, we're on Chrome 12 now... So they no longer officially support their own major release from a few months ago. I'm not sure what they're basing this on, but the major revision number doesn't seem likely. http://blog.chromium.org/2010/07/release-early-release-often...
I think people are putting too much/too little thought in to this version number thing. With Firefox's six-weekly release schedule now they'll define a major release differently from the version number.