Over the last few months I've done some serious refactoring in the Validator extension to make it more modular, less complex and easier to extend. The most significant change for code utilizing it is that the way parameters are defined has changed. In short, you should now use a new array-based syntax to define them or a class implementing IParameterDefinition (Validator has an abstract ParameterDefinition and a bunch of concrete deriving classes for different parameter types) rather then the old Parameter, which is now deprecated (but will continue to work for some time). All result formats in SMW have been updated to use this new kind of definition, and I will soon do the same for those in SRF and Semantic Maps. If you write any new formats, please use the new format. I have yet to update the Validator docs on MediaWiki.org, but you can find examples in SMWs result formats (and in the end the concepts is still the same as before).
Jeroen De Dauw
Don't panic. Don't be evil.