Although the future belongs to newer application launchers like Kickoff, Lancelot or Raptor, some users prefer the old K Menu style. Nothing wrong with that. That’s the reason why the plasma team made it really easy to switch the menu to a more KDE 3 like style. Unfortunately this “classic menu style” was quickly made and it missed a few features.
The classic menu style now supports separators in the menu…
… and it also offers the same context menu as the Kickoff style.
Both features will be available with KDE 4.3. Have fun!