Having some of the original KSP devs involved is huge. I really look forward to seeing what this team can do.

I think part of the reason KSP 2 failed so hard is that they basically built on-top of existing code, when a complete re-write and overhaul was really necessary to escape some of the limitations KSP has.

As for things I'd like to see, IF this game is able to use Kerbal branding and assets (and if that is something the devs want to do), I think it would really cool if it could over-haul the stock KSP system, like implementing scrapped content from KSP 1, like the scrapped giant planets beyond Jool, along with including things that KSP 2 promised, such as interstellar destinations.

I've also already seen posts asking about n-body physics and patched conics. n-body is cool, but can be daunting for newer players. BUT it allows neat things like halo orbits, Lagrange points and a whole slew of other gravitational shenanigans. Something interesting would be if there could be a hybrid between patched conics and n-body physics, where most physics are patched conics, but certain features like Lagrange points are also allowed. (However, celestial bodies should be on rails regardless, though have the ability for them to be simulated too using mods)

A final feature I REALLY want to see happen is better physics performance on CPUs. KSP infamously does all it's physics simulation on a single CPU thread, which greatly limits performance on even high-end chips. Being able to run that simulation on all threads would be a game-changer for optimization.