Honestly the Third Game has a really decent chance of coming out for the 3DS based on the production rate of the current games if we don't get it this year. Nobunaga's Revenge is gunna be what? March Release at the earliest? That would get it to us around Christmas? Maybe if we are lucky?
The concept of black and white is the concept of two drastically different individual ideas being juxtaposed against one another, much like good and bad, natural and artificial, and reality and fantasy. Black and White is consistent with those themes throughout the game. There are also many instances throughout the game where confuse black for white and white for black, much like Team Plasma's objectives. Gray is the merging of two different ideas mixed together into one singular, diverse idea. Though we tend to view the world in the two most fundamentally different colors, black and white, we need to realize that there is a spectrum of different shades between the two, also knowns as the gray. As I'm 99% positive that the next main-series game to be released is going to be Pokemon Gray, we will build upon this idea more.
One of the most notable ways to build upon the idea of two becoming one (much like Kyurem will likely have a form composed of both Reshiram and Zekrom) is by having the option to play Pokemon Gray on either the Nintendo DS or Nintendo 3DS. Gamefreak may either produce two separate versions of Gray, one for the Nintendo DS and another compatible with Nintendo 3DS, or, most likely, produce Pokemon Gray so then it operates fine on the Nintendo DS, but also take full advantage of the features on the Nintendo 3DS if played on the Nintendo 3DS (much like how Pokemon Gold and Silver, though made for Gameboy Color, can actually be used with the original Gameboy). I suspect that Nintendo, in order to maximize profits, will likely market the game for Nintendo 3DS by having the box labeled for Nintendo 3DS, even though it can still run on a Nintendo DS (Pokemon Crystal actually did something similar- its box says its for Gameboy Color, but the back also says it is compatible with the Gameboy Advance, which was just being released at the time of Crystal's release). This helps convey the idea that this current generation of Pokemon is a "transitional generation"- a Pokemon generation where no pair of systems is established to be the system mostly associated with that generation. Eventually, when the Ruby/Sapphire remakes come along, Nintendo or Gamefreak may just decide that the Nintendo 3DS is popular/widespread enough that they don't have to make it compatible with the Nintendo DS and only release the remakes for the Nintendo 3DS.
Though this will sound absolutely not-going-to-happen, but I [would like to] believe that Pokemon Gray will actually connect Pokemon Black and White to other generations. As said earlier, the concept of black and white are about pure this and completely that. Black and White, at least before the Elite Four, only feature generation V pokemon. In Gray, I think we'll start to have a few more pokemon from the previous generations migrate their way to Western Unova. We already have earlier Pokemon inhabiting the Eastern side of Unova, as well as being available via fishing and swarms, so by Gray, it seems natural for older Pokemon to have mixed with the newer Pokemon. And, as much as I know deep down that this just isn't going to happen, it would be awesome if Gray connected generation V to generations I-IV by adding evolutionary connections with Pokemon from generations I-IV. Namely, Luvdisc will get a way to evolve into Alomomola, and Pachirisu will be able to evolve into Emolga. Those four Pokemon are too similar to each other (well, not Luvdisc and Alomomola to Pachirisu and Emolga) to not be related. A pink, heart-shaped fish isn't related to a larger pink, heart-shaped fish? Yeah...
