Michael Sterns is leaving to start his own agency, Upstart Crow Literary, which will represent both children's books and adult (see the comments). He is joined by colleagues Chris Richman and Danielle Chiotti. They'll be accepting submissions as soon as next week. The web site should be live the week following.
Alice Pope has the deets here. Best to all who query.
Update 08/11/09: The web site is live, the agency is on twitter and facebook, and they have a blog. Enjoy!