Owlcat Games announced that they were working on a 40k Rogue Trader cRPG about 6 months ago, but they just released an alpha for it this week, and that gives us a bit more information of what this RPG looks like.
If you're not familiar with Owlcat Games, they're the developers behind the Pathfinder video games, Kingmaker and Wrath of the Righteous. I enjoyed Kingmaker but never could get around to finishing it, but Wrath of the Righteous thoroughly hooked me and I had an absolute blast playing it. Its not a perfect game by any means, but its definitely one of my favorite RPGs, and the setting of that game makes me incredibly interested in seeing these folks tackle a 40k game.
Rogue Trader seems to be like their Pathfinder games in that its an isometric cRPG where you play a customizable protagonist Rogue Trader with a party of NPC companions, including a Sister of Battle, an Eldar, and a Tech-Priest. And like the Pathfinder games it seems to be an adaptation of a tabletop rpg, in this case though its the Rogue Trader RPG. The game is set in the Koronus Expanse, a lot of the companions match up with the different tabletop classes (Seneschal, Navigator, etc.), and the stats and skills seem to be the same as in the tabletop. Character levelling seems a bit different, but its possible they've just organized it a bit more than the tabletop did.
Unlike the Pathfinder games, it seems that they're going exclusively with turn-based combat, and there seems to be a half-cover/full cover system similar to XCOM and other recent turn based games. My personal expectations for a Rogue Trader game would be a mix of trading, exploring, and fighting both on the ground and in space, and it looks like they're trying to go for all of that. There's space combat in the alpha (albeit in a very unfinished state), the world map makes it look like there's a lot to explore, and managing trade and stats like Profit Factor sounds like a core component of the game.
If you absolutely want to play the game this second, preordering gives you alpha access, but personally I'm going to be waiting until release date since that seems like a good way to burn out on the game.
Steam PageGameplay TrailerOfficial WebsiteRPG Reviewer discussing what's in the alpha