Groovy 1.7 provides the following new major features and enhancements:
- Anonymous Inner Classes and Nested Classes, for more Java-friendliness
- Annotation enhancements, with the ability to put annotations on imports, packages and variable declarations)
- Grape enhancement (the Groovy module system)
- Power Asserts, for more readable and expressive assertions
- AST (Abstract Syntax Tree) enhancements with the AST Viewer and AST Builder, for easing the creation of AST transformations
- Various dependency upgrades (including the ASM bytecode library to get ready for the JSR-292 InvokeDynamic bytecode instructions)
- A rewrite of the GroovyScriptEngine for more flexibility and rapidity
- Several GroovyConsole enhancements, like line numbers, a new output view, and more
- Various SQL improvements, like batch updates and transaction support
- and many more enhancements!
For some more details about all this features, you can have a look at the release notes.