As of this writing, there are a number of significant limitations in the generator and runtime.
The utilities have been tested with the documented XMLHttpRequest object. This object is supported by Mozilla-based browsers and recent versions of Internet Explorer. The code includes a fallback to ActiveXObject("MSXML2.XMLHTTP.6.0"), but we are not actively testing this fallback. If you need to work with older versions of Internet Explorer, you are on your own in adapting and testing the utilities. We'd be happy to accept contributions in this area, however.
Binding: Soap 1.1, only
The generator only support SOAP 1.1. Soap 1.2 support is likely to arrive soon. Other bindings are of questionable value.
Hypothetically, the XMLHttpRequest object in the browsers supports authentication. The utilities do not expose this support.
There is no support in the generator for complex types that use particles other than 'sequence'. There is no support for attributes. If you are coding schema-first, or you are using very complex JAXB annotations, you can come up with other particles, and the generator will refuse to generate code for these types.