A giant milestone was reached today. After 18 months of development, Umbraco 4 is in Release Candidate and what a candidate. It's the most stunning, fast, polished and flexible release of Umbraco ever and it's super stable. We recommend this to all new projects and we've made it the default release (you can still download 3.0.6 though).
In the last run we’ve concentrated on polishing the last bits including the installing experience, enhancing the support for validation of generic properties and we’ve also added an update checker than will check for updates every 7 days (configurable in the web.config) and show a message about upgrade to administrators.
But why have you read all this, when you should be downloading!