Omicron Major-like planetary systems.

[Durandal]

Well. If you are good at it, it should take about a month to make something like that. And if you are lucky to pass without any buggy problems. Question is, What kind of effect would it have on the game in general?

This guy knows what's up. It would be relatively easy to execute with the right skillset, but unless it serves a clearly defined purpose there isn't much point including something like this. This is the same reason you're not likely to see any more atmospheric systems unless they actually do something, like Darlington's which serves a purpose, namely helping to condense Newcastle.