Via Tom, here is a quick summary of the most significant changes:
- Validation Application Block. Allows you to centrally define validation rules using configuration or attributes, and easily validate data from anywhere in your application, including deep integration with Windows Forms, ASP.NET and WCF.
- Policy Injection Application Block. Provides a powerful approach for separating cross-cutting concerns from business logic using declarative policies that are attached at runtime to methods on your objects.
- Application Block Software Factory. Dramatically simplifies the process of building application blocks and providers through the magic of guidance automation.
- Visual Studio-integrated Configuration Editor. Edit Enterprise Library configuration files directly within Visual Studio.
- Environmental Overrides. Use the configuration tool to specify configuration settings that are common or different across multiple environments, and merge this information into configuration files to be deployed with your applications.
- WCF Integration. Easily integrate the Logging, Exception Handling and Validation Application Blocks into service interfaces built using Windows Communication Foundation.
- Pre-compiled, strong-named binaries. No need to compile and strong name the code unless you want to manage and evolve the code yourself.
That's just a quick list. The coolest thing to me is that there are no breaking changes in the core API, so you should be able to upgrade applications using EntLib 2.0 by just replacing the DLLs and updating the version numbers in the configuration files!