Just a heads-up to anyone who's playing: Nintendo is giving away free shiny legendary dogs at GameStops via Mystery Gift.
 
It's too late to get Raikou (that was up until today, Jan. 9th), unless your local GameStop is still somehow open, but:
 
Entei is available on Jan. 17th-23rd
 
Suicune is available on Jan. 31st-Feb 6th
 
They also come with unique moves unavailable regularly.
 
My Source, since the entire first page of Google has forum posts referencing it, but no one cites an actual news article.
 
Oh, and FYI (found this out the hard way)--you just have to walk into GameStop, and select "Receive Wirelessly" for Mystery Gift, no need to talk to any employees.

My friend got Raikou.  I need to get at least one of them so I can get whatever legendary they unlock in Black/White.

Damn, too bad I live in England.

neat! I hope I can remember to go get one, but I know from past experiences I always forget ><

Does this work for any Pokemon game? 
 
 
I think I got Diamond laying around somewhere..

" Does this work for any Pokemon game?   I think I got Diamond laying around somewhere.. "

It works for Diamond, Pearl, Platinum, HG, and SS. But only the American versions.
 
Any one of the trio unlocks an event to catch Zoroark in Black/White. This may also have something to do with the Zoroark movie, which is coming out soon in America, so when it hits Europe, they might do a similar release event. In Japan, they were released as a bonus for the pre-order tickets to the movie.
 
Oh, and I forgot to mention in the topic post: you can get as many copies as you have cartridges for. You just need to make sure you have the pokedex.
 
I got 2 Raikou, one in HG and one in SS.

Just a reminder, last day to get Entei in the U.S.