We aren't planning on working on MiniBrowser functionality - it's a WebKit development tool we're just using for now. Our focus is on getting the spec right and submitting our code to the WebKit trunk. There are ways of getting our prototype WebKit working inside a standard WebKit browser like Safari where print will work.
None of our samples were made with print in mind, though. As the layout shifts for the printed page the columns get too narrow, and sometimes the exclusion shapes collide. We'd need some separate print styling added to the samples to make them look a bit better. You may want to just use screenshots to share for now.