If you haven't heard (heck i just found out). Firefox is already in the beta verstion of 3.
Link

With the new firefox, you can expect new security updates.
But the thing that they are really proud about is it's new web rendering upgrade it well have.
Gecko 1.9 is the name of this Web Render. With it's 2 Million lines of code and 11k web rending relating fixes. You can expect that this well increase the speed in witch your browser interacts with a website.

They are also working hard on performance updates. Fixing over 300 memory leaks!

More info on this new firefox can be viewed at the link below.
Link

I used IE for the longest time. Ever since I started getting into designing websites I learned the value of Firefox. Almost any bug that I encounter in IE is not found in Firefox. Can't wait for the releasable candidate, I'll be one of the first to download

I died using IE for more than 5 years , then like 3 or 4 months ago I began using firefox !!! and hell yeah it's the best >