With the Wii pretty much dead until the arrival of the Wii U, Nintendo of America is desperately looking for new content to push to store shelves. That's perhaps the only thing that can explain the sudden and surprising decision to re-release Pikmin 2 on Wii so many years after its original release.
First released on Gamecube in 2004, Pikmin 2 was retooled to take advantage of Wii Remote controls. The updated release hit Japan and Europe in 2009--with no US release in sight.
However, the latest issue of Nintendo Power (via Nintendo Life) confirms Pikmin 2 will finally hit America later this year. While the US release is unlikely to feature any new content, it will whet fans' appetites for Pikmin 3, which should make its Wii U debut at E3 later this year.