Speculation: Did Scalia write the Heller decision?

The speculation circulating around Washington is that Scalia wrote the Heller v. DC decision. That speculation is based upon the fact that Scalia has supposedly not authored any of the decisions this term. (I haven't even checked this claim.) If this is true, it would presumably bode very well for the decision. I guess that the next question is: when will the decision come out (Wednesday or Thursday)?