Surprise.Here's the full statement from spokesman Joseph Zwilling (not yet available on the archdiocese's website):

Timothy Cardinal Dolan, Archbishop of New York, has accepted an invitation to deliver the closing prayer at next weeks Democratic National Convention. As was previously announced, he will also be offering the closing prayer at the Republican Convention on Thursday of this week.It was made clear to the Democratic Convention organizers, as it was to the Republicans, that the Cardinal was coming solely as a pastor, only to pray, not to endorse any party, platform, or candidate. The Cardinal consulted Bishop Peter Jugis of the Diocese of Charlotte, who gave the Cardinal his consent to take part in the convention that will be taking place in his diocese.

UPDATE: Sr. Simone Campbell, executive director of the social-justice group NETWORK, will address the convention on the evening of Wednesday, September 5 (she won't be offering a public prayer). "We're thrilled that Cardinal Dolan will be there too," NETWORK Communications Coordinator Stephanie Niedringhaus said.