The particles of our galaxy will be replaced with actual stars.
Particle Engine for Clouds on Planets. (Jupiter Cloud Simulation)
Realtime Weather on Earth
Accurate Space Travel effects(motion blur, stars looking like lines)
Directx9 or 10 support.
Possible Terrain Engine
Collisions (comet hitting planet, creating crater)
Rings of Planets replaced with space dust instead of textures.
Death of Stars
Galaxy Rotation
Galaxy Collisions
Actual Solar Flares
Particle Engine for Nebulas
Think of the possibilities!!! It will look beautiful!