Hmm, I'd like to once again bring up the idea that the Kree jump-started the Super-Soldier Program to combat the Skrull backed Nazis.... I still think that that's the most reasonable idea, but what brought both the Kree and the Skrull, and now Gah Lak Tus to Earth??
With the Humans as Weapons and the new initiative to boost the SS program (especially with the knowledge that we have Kree sleeper agents in SHIELD), I wouldnt be suprised if the Kree are trying to steer Earth into a position where it can defend itself from Gah, but why? Whats so important about Earth?
With all these Earth X ideas, there's the possibility of Celestial Eggs, but I think that'd piss me off. Celestials need to be introduced looooong before any revelations about their connections to the UU Earth.
....and as for the Origins of Mutanity.... I think we need to wait on that. Connect the Supersoldier Program to the multiple alien species on Earth, but wait a few more years for a revelation of that nature. I think we'd see the Inhumans sooner than find out that Mutants were genetically engineered to protect Earth. And in addition, I'd guess that Ultimate Arrival coincides with the Ultimates, Fantastic Four, and Spiderman, since they're all in New York. I think the X-men have played their part in the U. Galactus Trilogy.
Now... I dont want Watchers... At all. No Watchers. No Uatu, unless its some super-hacker who puts everything together from all the world's top secret files and realizes what the world's up against, but is bound not to interfere, because he'd be prosecuted, and he doesnt want to be arrested. (maybe his Hacker Alias could be Uatu...)