You mean the ships would have weapon slots, and the player could buy/steal weapons to them? Could fit in nicely.
But the nifty features aren't important. The really mind blowing new gameplay idea is. I couldn't just simply make a game just like Wazzal, it would be pointless.
Obviously there would be flying around in space within some sort of a map. And amidst there would be combat, trade and diplomacy. But what else?