I have no idea how it's supposed to work (or why the don't have a print CSS), but this works for pages written with Markdown:
- "Edit" the wiki page
 - Copy all text
 - Run a Markdown interpreter and pipe its result, e.g.: 
kramdown > /tmp/github.html - Paste your markdown
 - Press Ctrl-D to finalize your input
 - Open the generated HTML file and print it.
 
O_o
Posted by Arne Hartherz to makandra dev (2012-01-12 15:12)