A few days before these lines were written, Puppet Labs released a new open source project called TrapperKeeper, which can be found at https://github.com/puppetlabs/trapperkeeper:
"TrapperKeeper is a clojure framework for hosting long-running applications and services."
It has been presented in a blog post by Chris Price at http://puppetlabs.com/blog/new-era-application-services-puppet-labs, and currently there is really not much to say on how this product will affect the Puppet's ecosystem.
From what can be read and heard around, the impression is that TrapperKeeper will earn a lot of attention from Puppet Labs in the future. They talk about a new era after all.
My easy guess is that all the current and future projects written in Clojure by Puppet Labs will be based on this framework, starting from the same PuppetDB.
Given the terrific work they have done with PuppetDB, we can have great expectations on many different services that gravitate around Puppet.
I wouldn't be surprised...