I'm even using CMake 2.8.0 RC1 now, and still no output from make. Can it really be a CMake issue (higher version than required) or can it also be something else?

It is probably something else. Try creating an entirely new build directory and rerunning CMake.

Even after removing the build dir, creating a new one and rerunning cmake, the make command still doesn't have any output

Unfortunately I do not know why this occurs. Do you install KDE 4 from distribution packages?

Yes, I have KDE 4.3 installed from the default repositories.