Pearsons and VMware are joining forces. They have announced VMware Press and three upcoming book for the fall 2011 including one covering vCenter Orchestrator named "Automating Day-to-Day Administration of VMware vSphere 5.x".
Quoting the summary:
This hands-on technical guide to automating vSphere with Orchestrator teaches administrators how to save time and resources by automating their virtual infrastructure. Automation expert Cody Bunch teaches valuable practices and tool use through a combination of real world automation examples and case studies.
Cody Bunch is looking for feedback on specific use cases or workflows you would like to be covered in this book.