A new version is already out, this time with JSon catalogs generation. It is not properly tested, but Puppet seems to accept them. If someone knows how to get puppet catalog apply to download files from a Puppet server, I am interested.

I will probably write a sample application on top of WARP and modify the configuration of my Puppetmaster to redirect catalog requests towards it. This means that there could be an efficient replacement to the Puppetmaster soon.