The european side of the HeartGold and SoulSilver teaser site has said that the Shiny Pichu, which unlocks an event in HeartGold and SoulSilver, is to be distributed over WiFi this month.
Between March 5th and March 25th, anybody with a European copy of Diamond, Pearl or Platinum will be able to download the Pikacu colored Pichu via the Mystery Gift option. Identical to other regions, this Pichu will be level 30 and know Charge, Volt Tackle, Endure and Endeavor. It’s also holding an Everstone, is in a Cherish Ball and has a Classic Ribbon
It’s real function, however, is once this Pichu is traded to either HeartGold or SoulSilver. If placed at the lead of your party and taken to the shrine in Ilex Forest, you will encounter an even more special Pichu, the Spikey Eared Pichu. This Pichu will then join you, it will be at level 30, and know Helping Hand, Volt Tackle, Swagger and Pain Split. This Pichu is unable to evolve or be traded, and you can find out why by taking it and showing it to Professor Elm.
We’ll bring you more news when we learn it.
EDIT Friday 5th March: As annouced above, All European versions will be able to download the Shiny Pichu from today. It also turns out that all US versions and all Australian versions of Diamon, Peal and Platinum are able to download the same Pichu. Helpful if you missed the USA GameStop event, or imported a US copy of the game and obviously couldnt attend the event because you dont live in the states. If you DID get a shiny Pichu from GameStop, you will be UNABLE to get this Pichu as apart from Trainer and ID, they are the same Pokémon and you can only have one per cart.