You can find here some information on how to check out code and binaries for the project.

Code 

You can find the PKGBUILDs and any other related files on this repo on github.

Binary Packages

Binary packaging is expected to arrive in the near future.

For the moment you can add the repository for your architecture adding this snippet to your /etc/pacman.conf:

[archlinuxgis]
    SigLevel = PackageOptional
    Server = http://archlinuxgis.no-ip.org/$arch

Please be patient. The repository is hosted on a private system with low upstream bandwith.