Is this it?
As recent as July, the publisher delayed the title out of its 2009 release into early 2010, but then later delayed it further out of February until this coming April.
To make this announcement, Ubisoft thought it would be more efficient to send everyone at IGN a rock with the release date printed on it. Does this rock signify anything? Let's try breaking it open...
Update: Very big fail on our part. We just got the joke. As per Chris Roper, this means the date is now set in stone. So clever, Ubisoft.
Update 2: Wait a minute, perhaps this means the game rocks?