EDIT: A Big update on this topic is presented with PS CC 14.2! Now you can have linked smart objects, it works like in InDesign. Just go to File->Place Linked… and choose your .psb file.
This is the Promo video from adobe: https://www.youtube.com/watch?v=H6AIgoFDwlk
Is it possible to import an psb-file (saved smart object) into several psds, so when i edit the .psb the change is visible in every psd?
I only get it that way, that the psb is copied into the psd and the psb remains untouched.