After a recent review we have come to the conclusion that this feature is not at a stage that we'd like to see in Ubuntu and thus we are not pursuing to push this feature into Ubuntu 13.04.
Instead, we will be landing it in 13.10 once the current issues are resolved.
Ubuntu Users will be able to still use the feature by installing it from a Ubuntu R based PPA which will be rebased with any relevant R update. We will update this bug once the relevant details are documented.
In the course of the next couple of days we will also clean up this bug report with the necessary actions for R &S.
We appreciate your support and patience