We are currently working on DataMappings project which will be an easily alternative to achieve this behavior. The DataMappings are planed for the Q3 2012. We have a working example for ScheduleView which is very similar to the GanttView. You can find the example here
. The difference is that you have to implement IGanttTask interface on your Data Models. We will try to provide a working example for the GanttView till Q3 this year.
We're sorry for the caused inconvenience.
the Telerik team