A Pikachu Festival will begin on March 23rd at the Tohoku Pokemon Center.
This Festival will feature a number of Pikachu activities and will also have a Pikachu event distribution for Black and White games.

http://www.pokemon.co.jp/info/2012/0...html?i001=news

This Pikachu is being labeled the same as previous "Strongest" events (and is the strongest Pikachu event so far).

It will be distributed at level 100, with a Light Ball, and the moveset:
Thunder
Volt Tackle
Grass Knot
Quick Attack

The event runs until April 8.