planet.sun.com
We haven't released the standalone Roller-Planet application yet, but the .Sun Engineering team quietly deployed the latest bits at planet.sun.com a couple of weeks ago in response to requests from the Glassfish, SWDP and other teams for planet-style web sites. You can follow the links on the main page to find planets for Glassfish, SWDP, Sun India, Sun Alumni, Sun Java System Web Server, web services and globalization bloggers.
What's Roller-Planet? It's a community aggregation server, similar to Planet-Planet but with some key differences: it's got a web UI that enables groups of users to run their own planet sites, it's based on Java and it uses the ROME feed parser and fetcher. I've written about it before. We don't have a release plan yet for Roller-Planet so if you really want to try it you'll have to fetch and build it from the Apache Roller SVN repo.