So my winders update shows IE9 as an important update rather than the usual "optional", and I don't see a way to opt out of it? I know I can decide not to install, but it looks like it's not going to let me forget about it. The systray icon stays there.

I don't remember previous updates acting like this, or am I just forgetting since I rarely use IE?

MS is pushing IE9 a lot earlier than they originally planned. They were supposed to wait until June or so.

Is there any reason you wouldn't want IE9? It's a big improvement over IE8.

I usually try to keep a different version on each local machine for testing.

Noticed IE8 was listed as an update on vista - only way to remove it  was to uninstall the update(wasn't listed under program files)

Uninstalled IE8 with no problems - if feeling brave maybe you can install IE9 then uninstall it - could fuck things up royally

Take a look at http://ietester.com/