Linux Mint is an easy to use Linux distribution that is based on Ubuntu. One of the main advantage of Linux Mint has been its polish and ease of use. Recently with Ubuntu adopting the Unity UI, many Ubuntu users have migrated to Linux Mint.
Yesterday, the Linux Mint developers have announced that they will not base Linux Mint 11 KDE on Kubuntu. Instead, it will be based on Debian. It is worth remembering here that Ubuntu itself is based on Debian. By going to Debian directly, Linux Mint is cutting out the polish and features that Ubuntu brings.
Then why are they moving to Debian? Simple, the Kubuntu base needed too much resource and lacked performance. Kubuntu has never enjoyed a good reputed among KDE SC users. Most users of KDE SC will tell you that Kubuntu is one of the worst distributions for KDE.
Another issue that the Linux Mint developers have found is that the installer in Kubuntu has had a regression and cannot detect other operating systems. This will cause a big problem for new users and a big annoyance for more advance users.
Because of these issues, it has been decided that the next version Linux Mint 11 KDE will be based on Linux Mint Debian Edition (or LMDE as it is more commonly known).
No definite date for the release of Linux Minth 11 KDE has been set yet.