GNUstep is not GNOME or KDE; GNUstep is GTK or Qt. It’s not a DE, it’s a set of libraries to support development of desktop apps, backend services and CLI tools.
That’s where work that you’re doing on Nextspace comes in, I think? GNUstep core doesn’t have to declare “there is one DE and it’s NeXT-like”, it can serve for app development for other desktops. Further work can be built on top of that.
I have my own view of a GNUstep-based desktop — but I’m not feeling like putting enough effort into it to make it come true :)