With kernel.org being down for the past few weeks, there isn’t a clear indication of when they’ll be back up. In the meantime, its a good time to check if you are using mirrors.kernel.org on your Linux apt sources so you can continue to get the latest updates. As for developers, many are using github or other repositories to host their code. For instance, Linux Torvalds has released the latest build of Linux 3.1 via Github.
Debian Users:
Check your /etc/apt/sources.list. If you are using mirrors.kernel.org, change it to http://ftp.us.debian.org/debian/
References:
List of Debian Mirrors: http://www.debian.org/mirror/list
How to build your Apt sources.list http://wiki.debian.org/BuildingTutorial