The planets should be the same as they are generated off a specific "seed" number. One of the problems is that the planets themselves are enormous. I'm not positive, but they might actually be to scale.The game is an exploration sandbox game so expect more added features like Minecraft over time. Once they get base building, etc in there it will be a lot more fun. I've spent quite a few hours just finding plnaets and haven't even built a hyper drive yet.
Multiplayer would make it amazing. Hopefully they can do it but may not be that easy to implement if planets are generated differently for every user. Maybe they can allow players to meet at space stations?