The reason for the delay is to steer clear of competing products, which one can safely assume refers to Nintendo's Super Mario Galaxy 2, slated for a May 23 release.
Flip's Twisted World has been delayed a lot since its 2009 reveal. Originally slated for a fall 2009 release, it was shown off at E3 2009, but then was quietly delayed multiple times.
Right now, it looks like the game, which features music from Tommy Tallarico, is on the cusp of completion, but we'll have to wait until September to see it in full action.