To give the world in Dual Universe a bit more life, I think that there should be a bit more than just the planets and asteroids shown in trailers, but a bit more "stellar diversity", if you will. All these thing obviously won't be implemented at launch, and may not even be practical to implement.
Planets: There have already been several types of planets shown in trailers / discussed, and they have all been rocky, earth-sized planets. I personally think there should be various types of planets beyond the variation in biomes
Rocky Planets (similar to earth, as shown)
Gas Giants, with many asteroids / small planets orbiting them. The gas within them should apply pressure and crush any ship that goes too deep in, possibly to collect the gas for something
Airless planets - planets with no air, like earth's moon
Liquid planets - planets with all liquid and no land, buildings will have to either float or be underwater
Stars: There should be various types of stars, of varied temperatures and sizes, as well as several "oddball" stars
Neutron Stars - Very Heavy stars, remnants of smaller supernovae
Pulsars - Stars that emit radio / radiation pluses, could be used for navigation
White / Brown dwarf stars - small stars, burning very dimly
Binary Star Systems - Two stars orbiting each other
Nebulae: Nebulae should solar-system sized, with stuff in them (asteroids, etc). Engines should behave differently because of the gas, and the gas itself should be a resource to harvest and use/sell.
Black Holes: Found in deep space, they should behave much like real ones, with intense gravity and an event horizon. I do not know what the advantages of going near one would be, but they would have be worth the risk. Perhaps some rare particle radiated by black holes?
Comets / Meteor Storms: Small rocks / chunks of ice traveling at high speed through space. Would pose a threat of impact to large ships / stations, and planets, if they are big enough not to burn up.
Wormholes: Going into the realm of Sci-Fi, wormholes would act like natural stargates, connecting to another wormhole somewhere. They should be unstable, collapsing and re-forming elsewhere often
There could be any number of stellar phenomena in the game, fictional or otherwise, and I think they would add a nice touch of diversity throughout the emptiness of space