Following the asking of this question once more in
XML-DEV, Rick Jelliffe has posted an answer suitable for
inclusion in the FAQ.
The short answer is: "You must use a stream of XML
documents. The simplest way
to do this is separate each document with ^L, which is not
an
allowed character in XML and which is not used for in-band
signalling by common streaming systems."
For a fuller discussion of this topic, see Rick's
posting to XML-DEV.