I have done the following changes to YaST:Head
YaST:Head openSUSE_11.1 now builds on top of zypp:Head/openSUSE_11.1, otherwise almost no YaST package builds because 11.1 does not has the appropiate recent libzypp libraries. You need to have added zypp:Head/openSUSE_11.1 if you expect to install packages from there.
(This is a good example how hard it would be to build YaST:Head out of openSUSE, fixing this would be a good exercise).
YaST:Head openSUSE_Factory stays as it is, building against plain Factory.
YaST:Head openSUSE_Factory_zypp_Head is a new repo, which build against Factory, but using zypp:Head packages, thus showing how it would build with not yet submitted zypp packages.