I took the 'PPT-202 System Administration Using Puppet' exam today and as I've not seen it mentioned much on the forum I thought i should put a small post together. Hopefully the Linux section is an ok place to post.
I've been using puppet for a couple of years now as a small part of my work so in addition to a decent base level of knowledge I also re-read Pro Puppet (2nd edition) and worked through the sample exam. This book, plus hands on experence and a little bit of reading about the Puppet Enterprise product features should be enough to get you a decent pass.
The exam is multiple choice, including code samples, and most of the questions are quite direct. There is very little in the way of deliberately trick questions which made a nice change. The exam's quite cheap and was easy enough to prepare for due to my day to day work so I think it's a useful one to have on the CV for a sysadmin. I have no idea how big the market is for the cert itself but puppet is in quite high demand in London.
Resources -
Pro PuppetSample Exam