Yeah, having seen a bunch of previews now (still waiting on my copy's arrival in the mail), I'm pretty bummed by how many seem to have just been traced from other sources.
I've now seen two different pieces that traced this piece of concept art from Vincent Ward's Alien 3, for example:
There is some really fantastic material in the book. I love what I've seen from Tristan Jones, Dave Hallett, Matt Hatton, and RJ Palmer. I just wish, with this being a celebration of the 40th anniversary and all, there was a bit more effort/quality control put into getting pieces that were actually original from some of the other artists.