For the next three weeks you can download a Lv 30 Shiny Legendary provided you can connect to Nintendo with your DS to get the gift.
This is a precursor to the release of Black and White at the beginning of March (I put in a pre-order for Black yesterday). Trade one of the legendaries to Black or White to unlock a special event to capture a Lv 25 Zoroark.
http://www.serebii.net/blackwhite/zoroark.shtmlThis week it is a Shiny Raikou. The other Shinies are...
Entei Feb 14th to Feb 20th
Suicune Feb 21st to Feb 27th
These Pokemon can be obtained in Heartgold, Soulsilver, Diamond, Pearl and Platinum. Needless to say I had a busy time getting the first one yesterday (when I remembered). My HG and SS are UK releases whereas the older three I imported from the States, so it looks as if the events are the same for both regions as I assume the American cartridges access the US Ninendo.