Comment # 1 on bug 950879 from Wolfgang Bauer

Install kde-l10n-de, and dolphin (and other KDE applications) should be
translated.

Apparently this is not installed by default, even if you select "German" as
language in the installer (probably the same with other languages though).

I guess YaST still tries to install the old kde4-l10n-de package, which doesn't
exist any more...