Installer should utilize p2director and JBDS p2 repository created bt product build. That let us to have one installer for all platforms instead of five.
Size of installer is going to be more because of multi-platform bits inside p2repo and p2Director application included.
Installer based on IzPack has to extract p2repo first and then materialize JBDS using p2 director application.

Buckminister p2 director available from http://www.eclipse.org/downloads/download.php?file=/tools/buckminster/products/director_latest.zip

Literally now it can be installed like this:

director -r http://update-site-host/updates/nightly/ -d /install/target/directory -p jbds -i com.jboss.jbds.all -profileProperties org.eclipse.update.install.features=true
Installing com.jboss.jbds.all 4.1.0.201107071838.
Operation completed in 482798 ms.

or for local p2 repo archive

director -r file:///path-to-local-update/jbdevstudio-product-Update-4.1.0.v201107141200R-H631-CR3.zip!/ -d /install/target/directory -p jbds -i com.jboss.jbds.all -profileProperties org.eclipse.update.install.features=true
Installing com.jboss.jbds.all 4.1.0.201107071838.
Operation completed in 4827 ms.

Problems to solve:

• How to track p2 director installation progress
• Is there a way to install it without unpacking p2repo to disk first (as an option can try to pack p2 repo as a library and references it as file://installer.jar/p2repo!/)
• How to install TestNG which is part of JBDS Extra
• Would be good to have build for p2director app instead of using one from buckminister
• ???

Possible installation implementation:
1. Use director app and install it out of p2repo
2. Implements installer step based on :pserver:anonymous@dev.eclipse.org:/cvsroot/rt:org.eclipse.equinox/p2/bundles/org.eclipse.equinox.p2.installer