Pete Deemer, "Manager 2.0: The Role of the Manager in Scrum"
This article is about the often-posed question 'what about me? I am a manager, but Scrum doesn't mention my role. Where do I fit in?' Pete's answer is that many managerial tasks are very useful in a Scrum context, but that some tasks should disappear from the role description of a manager, such as 'Assign work to team members' and the like. Pete then gives a crucial advice: let the organization explicitly acknowledge the new role description, for otherwise your Scrum endeavor will be in danger.

Mike Cottmeyer, "The Agile Project Manager"
This article, which you can request at VersionOne, makes clear that traditional project management cares primarily about scope, while agile project management shifts focus to time and cost in order to deliver value to the business. Planning is feature-based, for a feature has business value. The agile project manager is a servant rather than a directive leader.

Pil2010: Agile ProductManagement With Scrum - Creating Products That Customers Love by Roman Pichler