The decision was made by Capcom in order to avoid the 2010 rush.
Capcom has updated their 2010 release list and has announced the delay of several of their most anticipated titles, including the North American release of Monster Hunter Tri for the Wii. They have moved these titles the next quarter, seeing releasing sometime after April 1, 2010.
The reason given for the delay is Capcom's desire to avoid competing with other first-quarter releases, preserving the value of their upcoming titles.
Titles that have been delayed include Super Street Fighter IV, Lost Planet 2, Dead Rising 2, and the international release of Monster Hunter Tri.