Due to the severe difficulties I had with "bootstrapping" to upgrade [core] from within the latest ArchHurd ISO I could find, I have started working in a Debian Hurd environment.
Currently, I have a working temporary installation of pacman so that I can build pacman packages for each package in [core]. I'm powering through this as fast as I can, and I hope to have each package from [core] in [testing], probably within a month worst case, no promises though.