Unfortunately, it does not. Only the licensed version of Saxon ("Saxon-SA") is schema-aware and XsltSE depends on the Saxon shared library ("sun-saxon-library"), which packages the open source version of Saxon ("Saxon-B").
At this time, there's no plan to support schema-aware xslt in Java CAPS 6. It would likely require partnering with Saxonica to release Saxon-SA with OpenESB, but that's not a conversation that's occurred as far as I know.
I'll discuss the possibility of adding schema-aware xslt with our product management.