"Every Debian developer is also an Ubuntu developer, because one way to contribute to Ubuntu is to contribute to Debian." — Mark Shuttleworth
KDE 4.2 has been released. Jaunty (current development release) users can do a full upgrade to get the latest packages. Packages for 8.10 (Intrepid) are in intrepid-backports.
KDE 4.2 Release Candidate 1 has been released and packages are available for Kubuntu 9.04 "Jaunty". Packages for Kubuntu 8.10 "Intrepid" are compiling and will be available shortly, check back soon if they are not all available when you read this. Read more for details.