I love Firefox guys, use it all the time if I could help it. But don't delude yourselves...if the situation were switched, do you really believe Firefox would prove to be more secure than IE? It's obviously a superior program, but if Firefox were king, Microsoft would probably be trumping the fact that they use ActiveX, and doesn't use Firefox's plugins, which are susceptible to attack.
(I'm not sure exactly how it works, just throwing a hypothetical thing in the air- DON'T flame me. If you like, educate.)
I doubt there's such a thing as a 'secure' browser...it's like saying there exists an encryption scheme that's uncrackable.
BACK TO TOPIC:
That doesn't make Microsoft's tactics any less deplorable, which is the real debate here. I have to see screens of this, the spreadfirefox guys could use it against them.