In many situations, customers have security teams and audit teams. They ask for granting users permissions to view audit web analytic reports, manage only security and permissions of users....etc. In most organizations, granting "site collection administrator" role to these teams is simply unacceptable.
One of the pretty features in SharePoint 2010 is the ability to add and define administrative roles by Farm Administrators, so they can grant approperiate teams roles to audit and manage security in different web sites in the Farm. To start creating such roles...
Permission Policies are on the most forgettable features despite of its great value. In order to avoid surprises, make sure to plan it early.
Edit 29 Oct 2012:
The above steps are specific to viewing web analytic reports and not to site audit reports. After completing these steps, the user will be abe to view the web analytics data as shown below...
For additional information about Web Application level policies, refer to: http://technet.microsoft.com/en-us/library/ff608071.aspx