I need to calculate progress and total duration of the parent activities based on the percent complete of child activities. Is this anywhere on the roadmap?
Duration of parent task already can be based on duration of sub-tasks ( though we plan to extend it in the next versions ) As for calculating the progress based on progress of sub-tasks - yes, we have such feature in plans ( most probably will be released till the end of the ear )
By the way, with existing Gantt component, you can attach event handlers on task modification events. It will be possible to recalculate parent date and progress from such event handlers ( it will require quite a lot of custom code, but still it can be done with public API of Gantt 2.0 )