Main links
The official web site of Stellarium for Java or S4J is here and the sourceforge project here.
The JIRA bug report project for S4J is here.
Subversion read only browsing is here, and the viewvc is here, and the official sourceforge here.
The Web resources are here.
Deployed versions
We have now 2 versions of the JNLP file. One with the big resources zip downloaded beforehand, and one were all resources are downloaded on demand from the web.
They are called respectively Standalone and Web version.
For the moment the Stellarium4Java WebStartversion needs Java 6 and is deployed on Sourceforge only.
The on going development version is here: Standalone (big download), Web (Download on demand).
Should works now but if stuck, please close and retry, it will fill the local file cache. If any ptroblem please activate the java console like shown and send the log in Jira. 
The first version 1.0.0 is here: To be release soon
The previous big download version is here (sourceforge) and here (java.net).
Stellarium for Java In the blogs
Stellarium for Java, alpha, in french
Stellarium For Java Alpha release!
Stellarium - Something New Under the Sun from Michael Levin's Weblog and Swampcast
JavaPosse Roundup '08 from the Swamp