For those unsure, an "Artist's Edition" is something that's been cropping up some in comic book circles lately, and what it is precisely is the original uncolored, sometimes un-inked (depending on the artist) pages as they originally appeared fresh off the artist's desk. That means the pages for this artist's edition will be in the same size as the original art (significantly larger than the original paperback release), and, judging from the fact that the images on Simonson's facebook page are inked, probably black and white inked, on extremely high-quality paper to reproduce the art as faithfully as possible.
If you're really into comic art, especially stuff in the old style, these Artist's Editions have been a real treat so far - very much looking forward to another excuse to mix my comic habit with my Alien habit.
Hope this clears up any confusion as to what the Artist's Edition is - any further questions, I'll make an effort to check back here.