This is the rumor linked on Bulbagarden in the Gen VI discussion thread, posted on Serebii originally:
Hi. My name is YellowGiant, and I am a visual designer by trade. My role in the Pokemon Franchise is minor, but has grown as of late to include actually aiding the development of the central games. I don't design the Pokemon, characters, or anything like that, but rather I am an assistant when it comes to designing the 3D models that GameFreak has begun to utilize in the recent games. My first big project was aiding the development of the PokeDex 3D App models, basically more of a clean-up member of the crew rather than a main modeler. I looked things over and such, along with other lesser members of the team.
Regardless, I am quite excited to share a bit of preliminary information regarding the new games that I know on here, because this is my first major retail game I've worked on, and since the game will be revealed in a few days, I thought I'd drop a few hints among the English speaking Pokemon community to get you guys hyped up. No proper names, of course, but general bullet points of what you guys can expect. I don't know how much of this information is being released next week, although I know they're going to reveal the titles at least, and a New Pokemon, but I'm unsure if game screen-shots will appear. It's up to you if you want to believe this or not, but here's what I can tell you if you choose to believe me.
* They are launching Three Versions simultaneously, collectively being called "Pokemon Trinity", but you'll have to wait to learn the names of the Versions themselves. There's more version exclusivity than ever before, and little cosmetic differences scattered about, but the focus here is not for an individual to buy all three...rather they're encouraging global and local trading more so than ever before.
* The game is in full 3D, although many of the backgrounds mix in hand-drawn models like old N64/PS games did, think of like the drawn backgrounds in Final Fantasy VII-X for an idea of what it looks like. All the characters and Pokemon, the ones used in PokeDex 3D, have models. Because of this, they're introducing trainer customization...players can now edit skin color, clothing, etc. for their own touch.
* The 3Ds is utilized in multiple ways...pressure-based (no more holding a button to run!) free-form movement as opposed to grid-based, utilization of QR codes and AR cards for various functions, and taking advantage of the improved Wi-Fi for some ambitious online play. The online functionality of this game is looking to be Nintendo's strongest output yet. GameFreak wants to make these the most social, globally-active Pokemon games yet.
* There's going to be a re-haul of various mechanics, although Gen V Pokemon can be transfered over, but may be "altered" in different ways as the system will adjust them to fit the new game-play elements. This includes restructuring of the type-chart, changed base stats, adjusted evolution levels, and simplifying the IV/EV system to appeal to both new and old players. All the old Pokemon are set to appear, but will be distributed greatly among the three versions. They're emphasizing trading, and using the 3DS, trading Pokemon with people around the world is easier than ever.
* Less plot-focused than previous games, more "free-roaming", but Gyms and the Evil Team still appear. It's an evolution of the Pokemon World (to fit in with the switch to 3D), as it's set after a major time-skip following Black and White 2...the new "Region" is actually a space colony reminiscent of those seen in anime such as Gundam and Nintendo's own Metroid. There's a large hub city which is the focal point of player-and-player interaction, and then multiple "biospheres" within the colony where Pokemon are raised, and where the Gym Towns are located. The biospheres open up as players obtain badges, leading to new free-roaming areas with more Pokemon. This setting, and the time skip, is being introduced alongside the changes in game-play elements to usher in a new "dimension" of Pokemon, you could say.
* A new Type is being introduced, called "Digital", but that's the translated Japanese name and it may be different when localized. Digital-type is "neutral", no weaknesses, resistances, immunities, but when it's the secondary type (there's only one planned Pure Digital), it doubles the weaknesses/resistances of the base type. Fire/Digital is 4X weak to Water, 1/4th resistant to Ice. There are many new Pokemon being introduced, not as many as Unova, including a handful of Digital-types and plenty of new evolutions of old Pokemon that have appeared following the time skip. Due to this, they'll be new evolutions that occur naturally.
* The mascot of the game is the only Pure-Digital Pokemon, it's actually the successor to Eevee...it doesn't evolve from it in-game, but was constructed using Eevee as a base. It resembles Eevee, except more reptilian and sleeker. It'll be debuting in the Eevee Mini-Movie, and is set to be revealed next week alongside the titles since it's a major player within the game. It's actually the lone Starter Pokemon, and all players start with it...its three, branching evolutionary forms are actually the Box Mascots as well. Utilizing the 3D models, this Pokemon has a unique and ambitious evolution system where its look will slightly alter depending on how you raise it, meaning that each player will end up with their own version of it more or less.
I'd...I'd be okay with all this.