It's great that the Kubuntu team (Philip Muškovac) provide these monthly releases of KDE 4.6.5 which are basically bug fix releases, KDE has release of KDE 4.6.5 and there available for download to Kubuntu user in Kubuntu launchpad.
Users of Kubuntu 11.04 or Ubuntu 11.04 can easily install/upgrade KDE 4.6.5 from the Kubuntu PPA (ppa:kubuntu-ppa). All bug and question should reported in Kubuntu launchpad.