L4WN M0WER MAN:well actually they arent going to make a halo wars 2 because the company that made it went out of business like right after they released the game. when well people actually use there head and think and not ask dumb questions like seriouly grow some balls dude.
The company was disolved, but quickly formed into two new studios, Robot and another one (can't remember name). If you look on Robot's website there's a bit that says they are working on new games. Alloysius has said it on these forums too.
It's a good guess that their unanounced project is Halo Wars 2. They seem a small studio, so doing something big from scratch would be tricky. With HW 2 they've already got the game engine that works and a franchise that sells, its the obvious choice for them.
As for space battles, no, it's just not Halo Wars, and not Halo in general. There's a canon of space cut scenes that lead to ground action, so more of that would be welcome, but let's stick to the battlefield. Better to get one thing right than have loads of different modes all incomplete.