Since Roger Lund already mentioned on his blog, I figured now's as good as of time as any to mention these whitepapers we created. These are a series of whitepapers made by the Technical Marketing staff to help you understand some of the new features in the 5.0 release. There are several short papers, each on different topics so you can pick and choose what you want to read about. I'd highly suggest giving them a read, and if you have any feedback, please do let us know.
*Update*
Here is a link where you can get all of the What's New Papers, including the SRM paper which Roger didn't have linked already.
(Note, these are or soon will be on vmware.com, but for the sake of time I'm just going to use the same links Roger used. Thanks Roger!)
What's New in vSphere 5.0 – Availability
What's New in vSphere 5.0 – Data Recovery
What's New in vSphere 5.0 – Networking
What's New in vSphere 5.0 – Performance