User blog comment:Avataress0/Cancellation Freak Out!/@comment-5188724-20121015102419/@comment-1038387-20121015103331

Three reasons I've heard so far:
 * CN's 20th birthday. They're certainly advertising it, but it doesn't explain the last minute change. Besides, the first broadcast was October 1, 1992 - so they're two weeks late.
 * "DC loses the rights to Milestone characters". A rumor based on an off-hand remark by Scott Lobdell about legal issues of Static, without any substantiation.
 * Stephanie Brown. Sure, DC doesn't like her, but it doesn't explain the last minute switcheroo (they'd have seen it earlier) or why the entire block was pulled. Also, as much as you want to blame Dan DiDio and his staff, they were all busy with NYCC.

So we still don't know who to blame for this. CN and DC have been less than forthcoming on the subject.