I'm excited that it's so soon, but I'm expecting a lot. I feel like DPPt were a tad rushed/not as well thought through, as there are an obscene amount of unnecessary aspects to the games. Plus, a lot of the "new features" weren't as solid and game-changing as the other games. In other words, (and this may be a personal bias since I've played R/B/Y/FireRed, G/S/C/SoulSilver, and R/S/E, but only Diamond), I feel like the games strongly developed as individual, stand-out generations from Gen I -> II -> III, but Gen IV just seemed like rehashed Gen III style play with different Pokemon, a new region, and new graphics (elaboration below). In the end, I hope Gen V retains those features most popular and beloved by seasoned Pokemon vets, but also introduces enough to set it apart from the other games.
A little more in-depth of what I feel
Generation I: The cornerstone of the Pokemon franchise, as these games introduced the basic concepts of Pokemon as we know them, as well as Kanto, the most famous region known to man.
Generation II: These games advanced the original trio like never before, adding elements of gender with both Pokemon and players, color, a clock and time-of-day/day-of-week system, a new set of Pokemon, moves, and HMs, and the epic continuation of the original story, three years later, that includes all 16 Gyms between the new Johto region and the old Kanto, as well as the chance to see the progression of Kanto characters years later and a final battle with Ash.
Generation III: In my opinion, these games really advanced the Pokemon universe in an individual and unique way, similar to Generation II. While the clock/time-of-day/day-of-week system was lost, and the typical addition of enhanced graphics, new Pokemon, moves, HMs, all set in a new region, remained the same, the environment, for the first time, played an extremely active role in the play of the game. Now I'm not saying the basic land/water/mountains/waterfalls/tall grass/etc. aspects common to the previous games, but for the first time you had vast weather changes on different routes, as well as a chance to really explore exotic areas, including a sandstorm desert, the top of a volcano, and a vast sea floor. The new Pokemon were, again, different and unique in regards to being of various types and new evolutions, and the storylines that included two teams of competing villains added a layer to the plot that, as a whole, was extremely memorable.
Generation IV: Again you have beautifully enhanced DS graphics and gameplay, new Pokemon, moves, HMs, and a new region, but this time things didn't feel as "brand-new" as they did with previous generations. While an emphasis was placed on dimensions, especially with Platinum and the trip to the Distortion World, the games simply rehashed characteristics of past generations (good ones, mind you), and introduced Pokemon that, for the most part, were new evolutions of previous generations (two new Eevee evolutions, third evolutions for Pokemon like Magneton, Magmar, and Electabuzz). Finally, it felt like the games tried to squeeze in too many legendaries than usual. This was also a slight problem in R/S/E, but it felt much more pronounced in DPPt. Oh yeah, and Poffins. Wth?
Generation V: Who knows what the next generation will bring, but this is what I hope for: rehashed and updated popular systems from the past, including environmental changes across the region, exotic locales, newly individual Pokemon, moves, and HMs that make sense, an appropriate number of legendaries, and, if possible, a connection to a region from the past (as I, to this day, find HG/SS to be the best games ever since you were really only half-done or less with the game upon beating the E4, not 80-90% like all other games).
In the end, I think the greatest game known to Pokemon fan boys and girls alike would be a massive story connecting all games in the franchise, allowing the player to effectively experience the entire Pokemon world in the same way Ash & Co. do in the anime series. I think a game that travels from region to region, with time changes on a yearly scale occuring similar to the anime, as well as the ability to gain all badges, challenge all E4s, travel to the Orange Islands, and catch all 493 (or more with Gen V) Pokemon would be the ultimate version. However, I personally feel such an undertaking would have to occur on a handheld, since that's where the franchise was born and is best known, and I doubt the DS has the capability of running such a staggering amount of data. But who knows? Perhaps the new 3DS will bring this dream to life.
