The Atmel Studio 6 has a great extension updater functionality, problem is it does not work for the newest release of ASF. Many people are complaining of failed installs in the built in rating system. I had a clean install of my PC anyway so I gave it a clean try. It did only work after multiple attempts and running the Studio with admin rights. I don't know if the latter did the trick, but I managed to download it.
Strange enough it does not install itself as the other extensions, you have to locate the file manually.
For those who did not manage to download it through studio, here is the link where I have uploaded it: https://www.rapidshare.com/#!dow...|168|1181537943|as-asf-msi-stable-22.214.171.124-win32.win32.x86.msi|302556
If someone from atmel sees this post, feel free to change my rapidshare link to the one which is found on the atmel.com site, but is not listed there.