It appears that Canonical and the Kubuntu team have decided that, due to the delayed release of KDE 4, the upcoming release of Kubuntu, 8.04, will not be a long term support (LTS) release, as it would usually be. Periodically, Ubuntu, Kubuntu, and other Ubuntu variants maintained by Canonical release a LTS release, which means that the release will be supported for 3 years on the desktop and 5 years on the server. Because KDE 4 will be released shortly before Kubuntu 8.04 is released, Kubuntu and Canonical are not comfortable giving the LTS tag to a release that incorporates KDE 4 this soon after its release. On the other hand, considering the amount of excitement around KDE 4, it seems like a mistake to not include KDE 4. The current solution, according to this announcement on the KDE mailing list, is to release two versions of Kubuntu 8.04, one with KDE 3.5 and the other with KDE 4. Apparently, neither will have the LTS release, though. Although this break from the standard schedule may cause some problems, considering the situation, I think the Kubuntu development team made the right choice.