I was speaking to some big Warhammer fans about it earlier, and we're all a little hyped for it given who is involved and what that could mean - my guess is it's going to be on Prime* (given who the main guy behind it is and his current/previous work), or Netflix, in which case they could very easily make it very close in tone to the stories and 40k universe.
People tend to forget how dark/harsh some of the streaming service series are, and how different US cable TV shows from the likes of HBO can be compared to US (and a lesser degree UK) Broadcast TV.
In some ways we're in an ideal time to be a science fiction fan, as the streaming services are looking for content and are far more willing to try something/keep it running for a complete season AND see how it does over several months (given they often release a full season at once) rather than as happened so often in US TV making a handful of episodes and cancelling after episode 3-4 aired..
*Amazon unlike pretty much any other TV of film production company has very good, up to date, and highly accurate data on both Book and Audio book sales and can/will consider what they can make from a TV or Film adaptation influencing book/audiobook sales (normally a TV production is primarily concerned with what it can make on advert sales).