Update Sept 27, 2014, early morning: this issue has been resolved. The dev and red channels have been updated, and new images have been created.

The red channel is currently moving towards requiring package signatures from the UBOS buildmaster before packages can be installed. There are some teething issues. If you run into them, temporarily disable package signature checking by editing /etc/pacman.conf, and changing the signature settings to optional:

FileSigLevel = Optional
LocalFileSigLevel = Optional
RemoteFileSigLevel = Optional