After installing JBDS on Mac I see two duplicate definitions of jboss.discovery.directory.url in JBoss Developer Studio.app/Contents/MacOS/jbdevstudio.ini
-vm /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java -product com.jboss.jbds.product.product -startup ../../../plugins/org.eclipse.equinox.launcher_1.3.0.v20120522-1813.jar --launcher.library ../../../plugins/org.eclipse.equinox.launcher.cocoa.macosx.x86_64_1.1.200.v20120522-1813 -product com.jboss.jbds.product.product -showsplash platform\:/base/plugins/com.jboss.jbds.product --launcher.XXMaxPermSize 256m --launcher.defaultAction openFile -vmargs -Dosgi.splashPath=platform:/base/plugins/com.jboss.jbds.product -Djboss.discovery.directory.url=https://devstudio.jboss.com/updates/6.0-staging/devstudio-directory.xml -Xms512m -Xmx1024m -Djboss.discovery.directory.url=https://devstudio.jboss.com/updates/6.0-staging/devstudio-directory.xml -Dosgi.instance.area.default=@user.home/workspace -XstartOnFirstThread -Dorg.eclipse.swt.internal.carbon.smallFonts -Xdock:icon=../Resources/JBDevStudio.icns -XX:MaxPermSize=256m
Maybe it has something to do with JBDS-2377 where MaxPermSize was added? (Probably not.)
I need to change this file every time to test a specific build of central, so I'm pretty sure this thing is new in CR1.