So among the last events to be given away to the 4th gen games, Celebi is next! Pokebeach and Serebii have posted that the Celebi event will be held the last week of Feb. and the first week of March. This Celebi can be downloaded to Diamond, Pearl, Platinum, HeartGold, and SoulSilver... and when sent to HeartGold and SoulSilver, will unlock a special side mission in the Ilex Forest.
Even cooler, once the Celebi is sent to Black and White, it allow the player to get a Zorua from an ingame trainer.
The Celebi is at Level 50 and is holding a Jacoba Berry. It knows Leaf Storm, Recover, Nasty Plot, and Healing Wish. The OT is "Gamestp" and its Trainer ID is 02271.