The release notes are used to highlight technical changes that users and administrators should be aware of: e.g. regressions, changes to configuration files, new ways of doing things etc.
The kind of document we recommend people read before installing/upgrading.
Fedora Highlights (?)
A marketing orientated document that runs down the features that made it into the final release. Uses screenshots extensively, and describes why the features are cool with a focus on how it applies to users and administrators (in separate sections) in day to day use. Should not describe how to use the feature and provides very little technical information: this is bling!
The kind of document we point digg/slashdot etc towards.
... what ever a traditional press release includes (sorry, someone will have to help me out here).