There are no DLC items available on the Nintendo servers at the current time (the US version has a letter with a built in item)
[I keep predicting that they've run out of new DLC items, but they keep surprising me]
The last new item was the "cucumber horse" - furniture item (released August 2010 in JPN), now gone from the server.

DiiLC can still be used to download items from conanac's special server.