http://www.pokemonplatinum.com/#/pokemon/rotom/
The website does reveal stuff about the secret key and how to obtain the different forms. It also mentions that the key is yet unobtainable, but will be obtainable later on.
Somehow I like that magnezone art, although it looks very plain. It's a fun card, too bad like all the other magnezones are way better, and even those are barely played anymore. Oh well, I'll probably end up buying one, even if it's only because it contains recent boosters for once.
Also, Mow Rotom has taken over my background :O