Works with the arch.iso, not with anything large though.. (this is not a kde problem, the mount command itself is not quite ready for the new millenium xd )
That... is not very useful. If you have a 100GB .iso (as some recent games) that you need to install, you now need 100GB x 3. The .iso, the extracted folder, then the installation. I'd rather have the simple easy step any other OS allows, which is to mount the iso for reading.