Related: Brightness fix
11Feb2010 Update: There are mouse issues with Karmic Koala so I would suggest you hold of from updating. See http://linuxbear.blogspot.com/2010/02/mouse-issues-with-ubuntu-karmic-koala.html
You need to run "sudo update-manager" in the command prompt.
This site has better details http://www.ubuntugeek.com/upgrade-ubuntu-9-04-jaunty-jackalope-to-ubuntu-9-10-karmic-koala-beta.html
