plans and estimates for supporting JDBC 3.0

I'd like to ask for help in figuring out where the current
implementation stands with respect to JDBC 3.0 compliance, with a
particular emphasis on support for distributed transactions.

The current source tree contains about 35,200 lines of .java code [1],
of which 7,800 lines are in org/postgresql/test/. The latter number
breaks down as follows:

7,000 lines in org/postgresql/test/jdbc2/
260 lines in org/postgresql/test/jdbc3/

There seems to be a fair amount of code that has already been written to
support JDBC 3.0.

As far as I can tell, XADataSource, XAConnection, and XAResource have
not been implemented yet.

| $ find org/ -name \*.java | \
| xargs grep -E "XA(DataSource|Connection|Resource)" | wc -l
| 0

Is there a plan for doing this and an estimate of the required effort?
(As far as I understand, support for the XA stuff needs to be added on
the backend side. Ignoring that for a second, are there any estimates
for the amount of work required on the driver side?)

Thanks,
Vadim

Footnotes
1. http://people.redhat.com/~vadimn/scratch/pgsql-jdbc/file-stats.txt