Japan's first WiFi event for the new games, Pokémon Black 2 & White 2, is ending tomorrow, on the 9th of August.

This WiFi event gives you a chance to obtain a Piplup with the following details:
Species: Piplup
ID: 07202
Ability: Torrent
Held Item: Metronome
Lv15
~Sing
~Round
~Featherdance
~Peck

Anyone with the Japanese version of the games can obtain it.

Source: Serebii

And after it, Genesect Wi-Fi event