When the rapid release schedule was first announced for Firefox last year, I was not a fan at all at first. My main reason or complaint was that in the past, each version of Firefox was somewhat "locked" to each distribution of Fedora (and other Linux distributions as well). For instance, Fedora 14 came with Firefox 3.6.x, and even though Firefox 4 and later versions were released for Linux, Fedora only released update packages for Firefox 3.6.x. My initial fear was that Firefox would become out of date even faster than in the past, and would require more difficult upgrade paths more frequently.
But, much to my surprise ever since Firefox was changed over to the rapid release schedule, Fedora has been releasing updated Firefox packages so that now we can stay completely current. With Fedora 16 (one of the currently supported distributions), Firefox 12 update packages are available which is the most up to date version, even though Fedora 16 originally shipped with Firefox 10. This is definitely good news and I hope this continues for the indefinite future. I'm not sure if other Linux distributions are following suit, but hopefully so.