Man, this is the same horrible mistaken notion people had in the Nintendo DSi topic. Why does everyone somehow think that the minute the latest version of something is released, that the previous version ceases to exist?
One, Windows 7 doesn't come out until at least summer of next year, and that's ignoring any (inevitable, in my mind) delays.
Two, Microsoft continued to support Windows XP for a long while after Vista came out, and I have no reason to believe they would suddenly act like it never existed once W7 ("wuh-seven") comes out.