oh sorry Ian, i guess i misread you.
i never really design/code in IE the way I do in FF and Chrome. i just debug IE. as far as i know there’s no live editing tools for IE unless you count firebug lite (which is a little janky compared to the real thing).
i personally use browserstack to fix problems in IE. I also use it to test for FF 3.6, old versions of Safari and Opera. its such a time saver compared to the old methods i used to have to employ to test for old/obscure browsers, being a mac user.