I've installed a Lubuntu Raring (which was the only ISO I had that would boot on the PC I tried to install Kubuntu) and installed kubuntu-desktop and then did do-release-upgrade.
Now I've got a Kubuntu Saucy (Upgrade without problems), but there are still remains from LXDE/lubuntu-desktop left. As an example, I can still select Openbox and LXDE as desktop environments on login.
I've found this answer to a similar question, but it's about converting to Xubuntu Quantal and I'd like to know whether there are differences in removing Lubuntu Saucy packages.