I don't know the details but I think it's like early access on Steam except it's like a year and half before release. I bet they get a bunch of visual benefits like stuff for strike cruisers or unique skins, maybe some sort of season pass to DLC as well. That's a guess though. I also don't know the exact cost details. All I know is I can't afford to buy any game on release and am stalking Steam Sales...
If it's a Steam greenlight thing (early access) then it'll be available from 25th June until official pre-order goes live. It'll also give you guaranteed access to betas and alphas of the game on PC.
As I'm getting it on xOne the Steam thing is irrelevant to me unless benefits transfer over account wide.
