Thanks for all help, I have a somewhat working (kind of) Gworkspace withing Windowmaker (that I need to read about how to config.. always been a foot-guy). It's kind of fun to see how much in OSX that's the same in GNUstep, I'm not totally lost, though I haven't touched Mac that much the last years.
However, I'm still struggling with ProjectCenter/Gorm. I can't open Gorm by clicking my interface-> app.gorm file. I found on google that I was supposed to do defaults write NSGlobalDomain GSWorkspaceApplication ''
and:
make_services
But not much happens there.. I hoped to write my first killer-app next week ;)