[CentOS] Repository for last packages (firefox, etc.)

[John Doe]

From: Yann I. <yann.i.672 at googlemail.com>
>I read an article on the site lwn.net (http://lwn.net/Articles/397034/). My 
>question (a newbie question !) is : where may I find these packages 
>xulrunner-1.9.2.7-2.el5.x86_64.rpm and firefox-3.6.7-2.el5.centos.x86_64.rpm ?

Tried yum update?
The text says "have been uploaded and are currently syncing to the mirrors"
You can check the mirrors status here: http://mirror-status.centos.org/

JD