The XML Schema 1.1 version of very good interesting features that are invaluable for my use cases. However, it seems to be relatively new. So I would like to get your feed b
1 - Which version of JAXB supports 1.1?
The schema-to-Java portion of the JAXB spec (JSR-222) does not cover converting schema 1.1 schema structures to Java classes. Starting from Java classes you should be able to map to the XML documents represented by these structures. Note: I am a member of the JAXB expert group.
2 - Which version of XmlBeans supports 1.1?
As far as I can tell XMLBeans does not support schema. There is nothing about it in any of the release notes.
3 - Does SOAP/WSDL support the 1.1?
I'm not sure.
4 - Does usage of this is going to put constraints on the soap stack that the clients of my API pick?
Yes, for example JAX-WS only supports XML Schema 1.0.
5 - Which version of JAXP started supporting this. I know JAXP has support for validating against 1.1 schema but not sure from which version.
I believe it is JAXP 1.4 (included with Java SE 6) that began supporting XML Schema 1.1. The version of Java with Java SE 5 does not.
6 - Are there any other things I should consider?
Which features from XML Schema 1.1 are you going to leverage?