I'm ecstatic about the improvement of orbital mechanics and how they affect space crafts at further distances. Most of all I'm excited about an already amazing game being improved upon and how I essentially feel like a kid in the candy store contemplating all of the possibilities.
If by some miracle I win this it will honestly be the most exciting thing that has happened to me in quite a while. I've never been more emersed in a game other than the original, with all of the add ons. Long live Kerbal