Interestingly, the soa tools are displayed only with "-Djboss.discovery.directory.url=https://devstudio.jboss.com/updates/5.0/staging/devstudio-directory.xml" but not with "-Djboss.discovery.directory.url=http://www.qa.jboss.com/binaries/RHDS/updates/development/5.0.0.GA.extras/devstudio-directory.xml" but these two are supposed to be identical AFAIK.
>From Nick's email:

To test this version of Central, add this to your ~/jbdevstudio/studio/jbdevstudio.ini file after the -vmargs line:

-Djboss.discovery.directory.url=http://www.qa.jboss.com/binaries/RHDS/updates/development/5.0.0.GA.extras/devstudio-directory.xml
or
-Djboss.discovery.directory.url=https://devstudio.jboss.com/updates/5.0/staging/devstudio-directory.xml

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators.
For more information on JIRA, see: http://www.atlassian.com/software/jira