When I was configuring SharePoint 2010 in Windows 2008 R2 to use Kerberos, I bumped into this Technet article, which discusses configuration of Kerberos for SharePoint 2010.
In the article, it advises to verify that Kerberos is used by looking at the Security event log and looking for Event 540. Well, event 540 never showed up. It confused the heck out of me. Apparently, event 540 is only for Windows 2003. In Windows 2008 R2, the equivalent of Event 540 is Event 4624. The following article mentions this: