XForms 1.1 is now a full W3C Recommendation. Compared to version 1.0, which went live a bit more than 6 years ago, version 1.1 offers lots of road-tested tools that make development easier and more powerful, including new datatypes and XPath functions, a significantly more powerful submission subsystem, and a more flexible event model.
And XSLTForms already supports almost all of the new goodies. -m