From the photos of the Flickr books from Derek Powazek and PT (and Derek's writeup) it looks like Qoop.com is to be the print service. The books look awesome, espcially the 13x19 "contact sheet" style print of all the photos. I think it would be cool to have all 15000 of my photos on several of these (or even better be able to select them by tag). Love to have one for example for all 3000 photos of the kid that I have.
The first surprise was a huge envelope with a 13x19 print inside. The print is a large grid of thumbnails from a seemingly random assortment of my Flickr photos. It reminded me a lot of the grid of photos I made of the first year of Ephemera, except with more whitespace.