I tested the following components for 2.0.x (from the 2009-12-16 nightly build):
geoserver-2.0.x-2009-12-16-war.zip
geoserver-2.0.1-SNAPSHOT-app-schema-plugin.zip
geoserver-2.0.1-SNAPSHOT-oracle-plugin.zip
The test configuration was:
geoserver-pirsa-earthresource-config.2009-08-11.r431.zip
https://twiki.auscope.org/twiki/bin/view/Grid/PirsaEarthResourceGeoserver
This configuration tests six app-schema feature types connecting to an Oracle database via a JNDI connection pool. Note: dbtype was changed to "oracle" to workaround GEOT-2598 ("Oracle" no longer works via JNDI).
I used apache-tomcat-6.0.20 under Sun Java 6 64-bit (jdk1.6.0_16.x64) on Fedora 11. I used Oracle ojdbc5.jar rather than the oracle14.jar shipped with the oracle-plugin.
I was able to deploy and start GeoServer and obtain good WFS responses for the six complex feature types.
Test result: PASS.
Next time we should tag before we test (e.g 2.0.1rc1), to avoid those last minute changes with unintended consequences. 
--
Ben Caradoc-Davies <Ben.Caradoc-Davies@anonymised.com>
Software Engineer, CSIRO Earth Science and Resource Engineering
Australian Resources Research Centre
26 Dick Perry Ave, Kensington WA 6151, Australia