Spots the Space Marine by M.C.A. Hogarth is back on sale in ebook and paper from Amazon.com. This is good.
No, I don't know what happened. Possibly someone pointed out to Amazon.com that Games Workshop DMCA notice citing violation of their trademark by Hogarth was...irregular, since DMCA notices are specifically about copyright.
Also, according to M.C.A. Hogarth's website, she is now speaking with EFF and matters on the legal front appear to be moving in a forwarder direction.