EDIT: The “Pokemon / forms” are confirmed to appear in the next issue of CoroCoro (see bottom right page).
A few images of a Pokemon Platinum pre-order advertisement have surfaced on 2ch, potentially revealing new Pokemon silhouettes. The photos were taken at a Toys R Us and a gaming store in Japan, where the advertisements are apparently available at Platinum pre-order booths. There are actually two versions of the advertisement, so there is a possibility these are genuine.
The text on the advertisements ask, “What’s up with these Pokemon silhouettes?” then say, “Hints are scattered on leaflets attached to Pokemon Platinum. More information related to the Pokemon will be given September 28th through November 4th.” This probably means that when Japanese Pokemon fans pick up Platinum (starting September 13th, its release date), leaflets will be attached to it containing clues about these Pokemon. Then, information will be released starting September 28th, potentially revealing what the Pokemon are or more information about discovering what they are from the clues on the leaflets.
The Pokemon have to be hidden Pokemon forms in Platinum or future fifth generation Pokemon, since clues about the Pokemon will be revealed after the game is released in Japan, and by then most fans will already know what is in Platinum. It would be pointless to “reveal” Pokemon or forms already obtainable, thus the reasoning that they are hidden Pokemon forms in the game that possibly will be unlocked through something like a Nintendo event or new Pokemon entirely for a future 5th generation game.
As with all “new” Pokemon and “forms” appearing on the internet before a game is released, the advertisements may be fan creations. The Pokemon silhouettes certainly look… weird, as if someone took Rotom and through it into a food blender with scrap mechanical parts. Time will reveal if these are fake or real though, so be sure to check back here for the latest! CoroCoro magazine scans should be coming out very soon, so hopefully, more light will be shed on the validity of these images.