Installing SOA tooling from JBoss Central with these jbdevstudio.ini settings:

-vm
/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/bin/java
-startup
plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.gtk.linux.x86_64_1.1.100.v20110505
-product
com.jboss.jbds.product.product
-showsplash
platform\:/base/plugins/com.jboss.jbds.product
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
-vmargs
-Xms512m
-Xmx1024m
-Djboss.discovery.directory.url=http://www.qa.jboss.com/binaries/RHDS/updates/development/5.0.0.Beta2.soa-tooling/devstudio-directory.xml
-Dosgi.instance.area.default=@user.home/workspace

Returns a list of older versions of the tooling plugins than is seen here: http://www.qa.jboss.com/binaries/RHDS/updates/development/5.0.0.Beta2.soa-tooling/

For example - this version of the BPEL editor is installed from Central:
BPEL Editor (Certified) 1.1.0.v20120501-0347-H6-Beta1-SOA

And this version from http://www.qa.jboss.com/binaries/RHDS/updates/development/5.0.0.Beta2.soa-tooling/:
BPEL Editor (Certified) 1.1.0.v20120522-2301-H13-Beta2-SOA