I thinking that the Fire Emblem: Mystery of the Emblem DS English & the PAL translation might be still under in development and might release sometime in Late 2011 or in 2012.
There are a few games that released 2 years after the Japanese Release.
Like:
Pokemon: Red & Blue[]
http://upload.wikimedia.org/wikipedia/en/c/ca/Pokemon_red_box.jpg
Jap: 1996 & US: 1998
Professor Layton 2-4[]
Professor Layton and the Diabolical Box[]
http://upload.wikimedia.org/wikipedia/en/thumb/6/6d/Diabolical_Box.jpg/250px-Diabolical_Box.jpg
Jap: 2007 & US: 2009
Professor Layton and the Unwound Future[]
http://upload.wikimedia.org/wikipedia/en/7/7b/Professor_Layton_and_the_Unwound_Future.png
Jap: 2008 & US: 2010
Professor Layton and the Last Specter[]
Jap: 2009 & US: 2011
Super Mario Bros. 3[]
Jap: 1988 & US: 1990