I see quite a few people excited over free-flight, but I think that's an assumption based on a video and not on any documentation (at least that I could find).
I agree that PvP on rails sounds far fetched and free-flight makes more sense, but I'm going to curtail my enthusiasm until I know for sure what it is I'm getting excited about.
There will not be a new planet and there is no increase to the level cap with this expansion. We really wanted to focus this expansion around space off of rails where you get to fight your friends (and enemies!)
To that point, there will not be any Space based PvE content with the Digital Expansion. It is only going to be PvP.