Ian, all,
A start of documentation for the server (and the POM now calls it
"fuseki-2.?.?" as this has become a more major change - all current
services will continue to function).
https://svn.apache.org/repos/asf/jena/branches/jena-fuseki-new-ui/docs/
The most important document is currently 'fuseki-protocol.md' which
describes the admin protocol.
The server currently supports creating new datasets while running
(including attaching to existing on-disk TDB filesets or anything
describable by an assembler). There is a short-cut mechanism to create
in-memory or TDB datasets by fixed template.
Andy