Well, like Daxdiv said, the title has already been released, but I wouldn't expect the movie to come out on DVD before sometime next spring. CN will probably play the movie at some point before the DVD is released as well, but we don't have any confirmed dates at all.
I always thought that they were going for all of the Diamond and Pearl movies to have some kind of connection between each other. At least that's what I've heard from a tiny summary of the plot of the eleventh movie. It's also a nice different approach to the movies too.
If they don't add any new Pokemon in the next generation, then I don't think that would be considered a next generation of Pokemon. That would be seen as the same list of Pokemon as before. Besides, for the new Pokemon games, they're always set in a new region and if there weren't any new Pokemon to go along with it, there wouldn't be much of a point in setting the game in a new region. The only exceptions would be remakes, like FireRed and LeafGreen, and spin-off games. Plus, there's also the whole thing of Nintendo wanting to make money off of the cash cow called Pokemon as well.
I honestly don't mind a revealing of a new Pokemon in the fifth generation. They do showcase one or two new Pokemon before they really get into the next generation, but that usually isn't for a good couple of years from that point anyway. I also recalled some people on this Pokemon forum I go to, Bulbagarden, complaining about now there hasn't been a new Pokemon revealed yet a few months ago so this is kind of an interesting opposite reaction. I'm not sure if the next Pokemon games won't come out until the next Nintendo handheld after the RAB comes out since I thought that they would go for one more set of game on the RAB before moving on. Either way, the new games probably won't come out for at least a good two years. Plantium just came out a few months ago so I'm not sure if they're completely ready to move that fast to the next generation of games.