[criddell]

As I understand it (and I just started using Pandoc today), pdf output requires TeX (or maybe it's LaTeX) from MiKTeX which I installed. By default, MiKTeX downloads dependencies as they are needed. For me, it dies when it tries to get xelatex.def because it's not on the server.

MiKTeX comes with an admin tool that has an option to synchronize repositories which supposedly fixes lots of problems, but apparently not this one.

For anybody that reads this and decides to get Pandoc and MiKTeX, I suggest getting the version of MiKTeX that bundles all of the dependencies. In the days of terabyte disks, I'm not sure it makes sense to pull down dependencies a few kilobytes at a time, especially if packages periodically go missing from the servers.

This is a side-by-side comparison of the HTML version and the generated PDF version:

http://imgur.com/a/Zkamk