While the core book for Rogue Trader is rather nice as a standalone product, it does make me look forward to additional products for this line. As such I thought it would be worthwhile to start a thread where folk can list content that they would like to see included in future books & expansions. Naturally I will start with some of my own suggestions, though I suspect some of these may be rather obvious ones.
More Ships!: The core rules for ships in Rogue Trader are a good start, but I felt this particular area was slightly lacking. While no one book can have everything I would like to see the number of ship types & hull classifications expanded in future supplements. Ideally I would like to see a supplement that focuses entirely on ships, ship components and so forth; not just Imperial ships of course but also a wide assortment of Xenos vessels as well. In specific I would like to see official rules to cover more Capital Ship types (Light Cruisers, Cruisers, Battle Cruisers, Grand Cruisers & Battleships of course) as well as some of the smaller ship types including landers & personnel/vehicular transports.
Planetary Tithes & Governance: I think Rogue Trader could benefit from an official set of rules to explain & manage the various forms of Tithe required by the Imperium. An entry and explanation (and mechanics) likely need to exist for everything from Solutio Tertius to Exactis Extremis and how these levels of tithe may affect the population, profit factors, trade, etc. Likewise as Rogue Traders can essentially colonize & conquer planets in the name of Him on Terra, some rules also need to exist IMO to handle the management of a planet more directly.