An updated Elite! would be very interesting. I have tried Oolite, but I found that (apart from visuals), too little was added. Yes, that made the feel very close to the original Elite!, but, frankly, that is a bit dated. I haven't played Frontier or any of the official sequels, so I can't really comment on these.
Things I would like to see are:
- More realistic economy. In the original Elite!, prices fluctuated with every jump, so by jumping back and forth between close systems, you could select your prices. Fluctuations should be slower and prices should depend more on distance. Also, you very quickly found out what to trade: Computers from high-tech to low-tech and food, liquor and furs the other way. I would prefer all goods to be viable and some systems to specialize in certain goods. And alien artefacts should be REALLY worthwhile to grab, unlike in the original where the price is just average.
- A 3D star map. The original galaxies are flat and rectangular. A 3D local map and spiral-galaxy global map would be nice. One galaxy should be enough, though, if it is large enough.
- Worm holes: A few connections that allow you to travel long distances to specific destinations.
- No "ultimate" weapons like energy bombs.
- More choice of player ships and upgrades.
- Possibility to buy or hire escort ships.
- Exploration: Earn income by surveying unexplored systems.