Whatever they do they have to make it 100% clear from devs on down to end user the sort of feel they are going for, or they will end up with dust's lack of focus.
Lack of Focus? In the beginning yes. It's reception was not well received since the "finished" product never had the companies buy in. The niche presented was too nichey. The end game and all its flaws had development that cared, and I can only imagine what Rattatis initiative and frugality with Maria Sayans Midas touch would look like on the next gen, but instead of talking about the failures I ask what could be done now in order to create content in both games that will hopefully become commonplace with the pending game in the works.
I say none and don't bother with any 'integration' attempts, but my opinion counts for nill
Both games operate at significant differences in timing and duration of combat, there's a fundamental gameplay disconnect in the concept of marrying the two (in my eyes).
Only thing you might be able to do is have stations/citadels/whatever under timers showing up on dust servers as upcoming battles to join? I dunno.
Make it a standalone singleplayer story / pvp game with the proper scope and depth of the amazing setting. Most of all it should feel 'alive' that you are inside the IP, interacting with that world. Gunfights in high sec stations, shootouts in markets on planet surfaces in lowsec. Boarding actions on capital ships and battleships. You've got a wonderful, busy, wide universe to play in, don't spend it only fighting over big open landscapes?
But does this game want to be a squad, tactical shooter? A big open world vehicle mega battle? A run and gun infinite respawn pew pew fest? Beats me.