May 28, 2010 is the longest you’ll have to wait for an English version of Metal Gear Solid: Peace Walker.
That’s when Konami’s European branch will release Peace Walker in Europe. The press release mentions co-op play and “a twisting plot that will delight and surprise as the game is played,” but doesn’t mention the Vocaloid collaboration.
Konami has yet to announce a North American release date for Metal Gear Solid: Peace Walker, but it should fall between March 18 (when the game launches in Japan) and May 28.