I've never put together a spin before, so I'm not sure how much help I can give aside from testing.  What I'm trying to help achieve is a Fedora spin that is basically the same as the Rawhide, except uses stable (~6 month old) packages.  

This is my motivation:  I'd love to never have to worry about distribution upgrades, big modifications to my MBR/EFR, changing repo URLs, and all the other junk that goes along with upgrading the distribution from x to x+1.  Without that stuff the OS would be much easier to use over time, and certainly something I would have no problems recommending to a new Linux user.  As it stands now, I think the distro upgrade process of Linux distros is an unnecessary difficulty for most desktop users, when using 'yum' for continuously updating the packages would work just as well.