Mr.MewMew

While that would be insanely awesome, no, there is absolutely no way that will happen. Gray will be a third sister game like all the others, with aspects of both Black and White in it, although seemingly missing something, as always. But it will involve Kyurem more, just as the third sister game (minus Yellow Version) always does with the third, lesser-known about being of the trio. So no, not a sequel, just another remake, more than likely one that will be on the original DS platform and not specifically for 3DS (even Nintendo and Gamefreak know not to advance like that all of the sudden).

I would definitely say that the things hidden in the programming, like the two moves and the God Stone, are things that Gamefreak intentionally took out for use in a sister game (Gray version?). But the exact use of these could be tricky. My own professional (in my own mind) opinion is that the God Stone would restore Kyurem to it's former self (it being the corpse of the at one time single dragon), much likethe Dark and Light Stones contained Zekrom and Reshiram. Also, since at one Kyurem could have been one entity containing both of these two, it was possibly (very stretched here) triple typed? Possibly Dragon/Fire/Lightning? And then as said before, the corpse rose with the Dragon form and Ice powers from it's descent back to Earth? So in that scenario, it could have both ultimate attacks, since they both involve ICE and Fir or Electric, which shows it's connection to the other two dragons. I love talking about this, I feel like a crackpot dispelling rumors about the JFK murder!