Interestingly...
Just this afternoon my girl's laptop got an 'auto-update' from MS including IE7. We decided to install it since recently IE6 had been problematic for her lately anyway.
Big mistake...
She's really into blogging right now so this was our particular criteria... and it failed bad...
For some reason Blogs that display just fine in Firefox, Opera, IE6, and even older versions of IE, failed miserably in IE7. Text and images completely sliding out of their container elements... off the page actually. Text in a lonnnggggg column only 6 or so characters wide... Completely unreadable.
Lasted about 3 minutes...
She asked me to let her try Firefox, so I installed it for her, showed her the basics/differences to what she was used to in IE6.
Her first comment was, and I kid you not, "This is soooo much faster..."
Sexy skins, tabs, innovative extensions, pretty toolbars... whatever.
First and foremost the browser has to work correctly at what it's supposed to do. And that's displaying web content.
Point of view from a decidedly non-techie personality:
IE7 - 0
FF2 - 1