This is saddening. /: I'm not a KDE fan, but it still hurts to lose a member of the Ubuntu family!
Well I do see hat they're doing, they just recently gave official recognition to Lubuntu which which is a specialised spin with the LXDE interface
so they currently have
Ubuntu = Main distro using their Unity desktop
Kubuntu = *deprecated official support* another high resource competitor to their Unity interface
Xubuntu = until recently XFCE was the goto light alternative, though of late XFCE seems to have filled out more feature wise, and realy is kinda taken the place gnome used to have....
Lubuntu = A very recent Official addition, and honestly my favourite "light" desktop choice and does contain a lot of advanced features