WMG / Star Trek: The Next Generation/Doctor Who: Assimilation²

Q will ally himself with the Federation against the Borg and Cybermen

Qs are time lords. Gallifrey is the Q-Continuum.
Obvious, really.

Gene Roddenberry is a Time Lord
Hence why Star Trek is able to simultaneously exist in a parallel universe and be a TV show that Rose (and Izzy) have previously referenced.

Guinan is a Time Lady
Go reread her conversation with the Doctor, it might as well be official.

The events of the crossover indirectly lead to Star Trek: First Contact happening
It's all too easy to extrapolate from the end of the final issue, with the Borg stating that they intend to master time travel as a result of their experience with the Cybermen and the Doctor. Kinda makes the whole thing a bit of a Nice Job Breaking It, Hero! moment for the Doc...

The merging of the Star Trek and Doctor Who universes is Decade's fault.
You know it is.

The reason the Cybermen in "Nightmare in Silver" are like the Borg (the ability of rapid adaption) is due to this encounter.
Furthermore, the cyber pollen seen in "Death in Heaven" are a result of reverse-engineering Borg nanoprobes.

The reason Star Trek is fictional in the Whoniverse is because the thoughts of the writers tuned into events of the other Universe
  • Like with Earth-1 and Earth-2.
    • Likewise while not common knowledge anymore Doctor Who was once a television series on Earth, even to this day it's a cult Holo program series.

The Merging never ended

The Borg/Cybermen used time travel to create the Star Trek TV series
This temporal disruption is why the Doctor's memories of things like Klingons and the Federation are so inconsistent- he remembers the Federation as both a laughable Earth fiction to be dismissed and genuine history, simultaneously, and consequently his memory goes into a weird kind of diffraction pattern. The intention behind this sinister plot is not yet clear to me, but it may be another attempt to squash humanity's spacefaring spirit to make them less formidable foes in the future... somehow.

The Borg and the Cybermen are two splinter fleets of the same "race"
Tenth Planet confirms that the original Cybermen came from Mondas, a planet that inexplicably wandered out of its (our) solar system. Suppose that at one point the world wandered into the Delta Quadrant and some of the recent Cybermen used their then-still-rudimentary spacefaring technology to spread into other worlds in that area. Divergent evolution in their mechanization techniques led different batches on different worlds to have slightly different characteristics, but they do share an origin.


http://tvtropes.org/pmwiki/pmwiki.php/WMG/StarTrekTheNextGenerationDoctorWhoAssimilation2