We do not support master backlog in the way you want it as we consider each project specific in terms of project template and migrating stories from one project to another may cause validation problems.
In your case we suggest to create one big project and create hierarchy of iterations to simulate subprojects. something like this:
- Project 1
- Project 2
- 2012 - Release 1
- 2012 - Release 2
This way you will be able to track each subproject separately - each iteration will show its own burndown; on the story and task board one can select just the iteration for the subproject he is interested in; all the reports can be generated by iteration, so work on separate subprojects will not mix up.
We will release the cross project view till the end of the week and you will be able to create new hosted trial and try the new xView functionalities.
All the best,
the Telerik team