Many thanks to rockettruth for the link!
You can now order a copy of the premiere issue of the John Wick comic book for $3.99 here. An autographed copy by Greg Pak is going for $49.99 for collectors and is here. The following synopsis is given:
When a young John Wick emerges from prison and embarks upon his first, epic vendetta, he comes up against a strange, powerful community of assassins and must learn how to master the Book of Rules that guides their lethal business. What are the Three Bills? Who is Calamity? And who was John Wick before he became the Baba Yaga? Here for the first time, read the thrilling origin story of John Wick, from “Planet Hulk” writer Greg Pak and “Dark Horse Presents” artist Giovanni Valletta.