New Pokemon in Platinum

[Kenny]

From what I can tell, the Eevee evolutions are fake, for the simple reason that Nintendo has never tried to increase the Pokemon count within the same generation. They may have made accessible legendary Pokemon initially not accessible, but they never actually added to the count. On the other hand, new Rotom forms are plausible, because there is precedent for new forms to get added in the mid-generation refresh (this precedent was set by Deoxys, IIRC).