Basic and elementary questions which arise in the context of fully developed turbulent systems are still open and discussed controversially. Some of these questions are: - What is the relation between Eulerian longitudinal and transversal structure functions? - Is there a relation between Eulerian and Lagrangian fluctuations? - Can we say something about the energy spectrum in slightly more complex systems as e.g. in magnetohydrodynamical turbulence? In my talk, I will present different viewpoints and possible solution strategies.