According to the official website of Visual Arts, the anime of Little Busters! was officially announced.

Little Busters! anime official website
Trailer (Youtube)

Note: This news is not an April fool's joke since Visual Arts posted the information specifically on March 31st.

Source: Visual Arts official website

Update Apr 2nd
Mangaka Zen, the author of Little Busters! Ecstacy complained that she had been preparing for the April Fool's joke of "Little Nya-sters" anime but Dengeki's premature leak spoiled her effort.

Zen's joke illustration of "Little Nya-sters" anime It says "The mission will start this autumn."

She said, "Yeah you're right. They leaked the information! I sacrificed myself to prepare the joke but our plan was completely ruined. It's so funny huh? You can ridicule me! Hahaha! (sob)"

Source: Zen's official website

Updated on April 3rd
The President of Visual Arts announced on his twitter account that the cast of Little Busters anime hasn't been fixed yet but the anime will be aired not so far in the future. He didn't reveal the production studio but he said the producers have been under tremendous pressure since they are aware of the high expectation of the fans. He said the quality of the trailer was not high because Visual Arts themselves made the animation using image sequences sent from the production studio.

Source: Baba's twitter account

Little Busters! on MAL