Following the Roadmap version 4.0.0 Alpha2 of Hibernate Validator is now available. This implementation is based on JSR 303 Specification 1.0.Beta4. The distribution contains everything you need to get started. If not let us know what you are missing.
The main focus for this release was to implement groups, group sequences and the redefinition of the Default group for a class. Implicit grouping will be available in the next release. Next to the grouping feature ConstraintValidatorContext and TraversableResolver are now properly integrated in the implementation and all builtin constraints as per current spec are also supported.
Naturally there were also several unrelated bug fixes, especially around the methods Validator.validateValue and Validator.validateProperty. Check the change log if you want to know more.
It would be great if you could try out this release and provide us with some feedback.