man, it is using way less memory for me than 1.5.  And a good bit snappier (especially on javascript-heavy sites).
phaneuf_train - 
Brief Firefox scoop.  I use it mainly because I'm multiplatform, and like to use the same browser everywhere.  Also, the addons make it far and away better than any other browser (adblock plus + filterset.g, bugmenot... and possibly the greatest thing ever in 
Greasemonkey).  I really can't deal with the web anymore without those little "fixes" that make it palatable for me, now that I'm so used to them.