That's definitely nice for me the developer, but it doesn't really matter much for me the consumer. It's a pretty small handful of sites that haven't been wrangled to work in IE. Maybe we'll see more growth in CSS3, Canvas, etc, in use on sites that care less about IE, but for now in practice, that's not much of a difference.
Definitely a valid point, most websites render fine in IE7 and up (though IE6 is losing ground quickly). However, though most people won't examine it beyond their use, easier development generally means better web experiences, so it is in their best interest to use a (more) compliant browser. If nothing else, it's good to encourage more to use FF over IE for that reason.
And personally, I love CSS3 tricks that JavaScript isn't really ideally suited for, and Canvas is a very welcome addition.