Primal Reversion?
I've been thinking that Sun and Moon will deal with Primal Reversion the same way X and Y dealt with Mega Evolution. Before I get into why I'm thinking that, let me make it clear what the difference is. If you already know the difference, feel free to skip the next two paragraphs.
Mega Evolution requires a mega stone and a key stone. Mega stones are created when the various evolution stones have become irradiated by the powers of legendary Pokemon. The only identified way that mega stones were created was through the power of Xerneas or Yveltal through the ultimate weapon. However, meteorites also contain mega stones on occasion, implying that Deoxys can create mega stones as well. The origins of key stones is unclear, but they somehow activate the powers within the mega stones. The only exception for this rule is Rayquaza, who ate his mega stone. Because sometimes you're hungry for radiated meteorites! Professor Sycamore theorizes that mega evolution is dependent on the bond between trainer and Pokemon. Since the wild Mewtwo cannot mega evolve until you capture it, that may very well be true.
Primal Reversion only requires the Pokemon in question to be holding the appropriate Colored Orb. A trainer is not required for Primal Reversion to take place, and the trainer cannot control it in the same way they control Mega Evolution. Also, the Colored Orbs are not radiated stones, but connected to nature and allow the Pokemon holding them to draw power from nature itself.
Now that the lesson for everyone that ignored the story of Pokemon is over, let's get to why I think Primal Reversion will be the thing of this generation.
1: Location
Whether the location is based on Hawaii, Indonesia, Central America, or someplace else; it is quite clear that we are dealing with a very "wild" region. The presence of so many vehicles, particularly a mobile Pokemon center, implies that it is sparsely populated. What's more, most of those vehicles are trucks, which are known for their excellent traction in the brush.
Also, the backpacker in X and Y that is from this region is a good hint. Of all the trainer classes in existence, they picked the backpacker to be our first impression of generation seven.
2: Sun and Moon
The second we heard those titles, we all thought about what sun and moon gods the mascot Pokemon would be based on. The name indicates that the forces of nature, particularly the Sun and Moon, will be key to the plot. This would fit quite well with Primal Reversion.
3: Affects on competitive game-play
Mega Evolution was introduced for two reasons: 1) power up certain Pokemon and 2) make team-building more straightforward for new comers. Primal Reversion would help more on both counts. You could give Primal forms to generally useless Pokemon (Farfetch'd comes to mind) and to power up some Pokemon that might go under-used because of Mega Evolution (such as Scyther). Of course, I believe Game Freak will find a way to limit us to one Primal Pokemon per team, possibly by giving us only one Colored Orb per game (a Yellow Orb and a Violet Orb perhaps) and make it impossible to trade away. So we'd be limited to our one Primal Pokemon per team, and new comers on the competitive scene would have two Pokemon to start with.
So what do all of you think? Am I just reading to much into it?