Scott Guthrie covers the new features of Preview 5:
These new features include:
- The ability to publish a single action URL and dispatch it differently depending on the HTTP Verb
- Model Binders that allow rich parameter objects to be constructed from form input values and passed to action methods
- Helper methods that enable incoming form input values to be mapped to existing model object instances within action methods
- Improved support for handling input and validation errors (for example: automatically highlighting bad fields and preserving end-user entered form values when the form is redisplayed to the user)
Scott covers each of those items in his blog post.