Heard some news that IE6 might be auto updated to be IE7, if the
user is running XP. Windows 2000 users and below, no worries. You
will be stuck with that buggy, full of holes, unsecured IE6. MS has
no plans to upgrade you.
And you can't run 2 different versions of IE. If it gets upgraded,
it can't be downgraded. As per every version of Windows. Unless you
know how. It's troublesome.
If you need both the old and new versions, I guess you need a spare
PC then.