well the original release date mentioned by Kalmah on their official website is April 2nd. You can pre order it on a website, this link is found on their myspace. but the website is NOT in english.
Yes, that was the official release date. Now it has been moved, due to licensing issues with Spinefarm, etc.... I cannot be sure, because I cannot remember where I saw it, but I am almost positive it is April 23.