Games Workshop has released its samples to the digital versions of the Militarum Tempestus codex, and the first thing that stood out to me, is a page for the Commissars. The codex is for Scions and Commissars, and the stat page for Commissars was shown in the samples.
Not to mention that there is a good amount of artwork, and background in the sample. This is one of the first samples that really had me reading the background, from the formation of the Scions and their indoctrination, to the different known detachments of Scions. It was a good read, with some great new artwork.
I did not that Commissar Lords are still here and Commissars come with their Aura of Discipline. Definitely looking forward to this book release.
Of course you can check these out by following the links.