It's about time. X4 fans have been wanting the Boron expansion since before Cradle of Humanity and Tides of Avarice, hell, maybe even before Split Vendetta. (I didn't get X4 until after SV was out, so I don't know for sure if that was the case, but it wouldn't surprise me.)
The trailer music is, of course, based on one of the best tracks from the previous games.
Looks like they opted on just having the Boron wearing floaty suits and keeping everything else the same, which I guess makes way more sense than doing what would have been accurate lore-wise, i.e. having all the Boron ships/stations completely filled with water and making all the other races have to deal with that.