As for whether the universes will ever come together again, I guess time will tell once Badlands hits and we see how compatible with the Alien movies the Predator franchise's future ends up looking.
As for what I personally want, I am personally of the mindset that Alien and Predator work best separately. I understand the appeal of AVP, though, and now that 20th Century Fox Studios is under new leadership and seeming to have success with the brands individually, I know that down the line there's going to be some sort of AVP reboot that will (thankfully) have nothing to do with the two movies we already have, so I guess my thoughts are: f**k it, it's gonna happen eventually, I just hope it is good.