Whether or not you agree or not with the Beta thing… this is not the place for that. Please leave that elsewhere.
A couple site offer the Beta download (not free) but it does give a free preview. That said you can take a look at the (what I am sure is tentative) table of contents listing all regiments, regiment creation, all 12 specialties, the confirmation of vehicles, and the setting enemies. This gives a HUGE insight into whats in the book (as much as free gets you). And "Comrades."
I think Chaos as an enemy will me interesting, like the Stigmartus enemies of Deathwatch … but scarier. The Dark Eldar similarly.
And it seems that all characters get a comrade, a sidekick from the sound of it. Dunno yet.
I'm happy with the ToC so far!