We create new products and releases for those products. Over time it may become apparent that the product, in fact, needs to be split up into additional products. Then, the releases must be moved.
Each release contains phases and milestones with dependencies and/or tasks. We would like to be able to move an entire release to a new product and maintain the integrity of the phase/milestone details as well as the features and requirements.
This is why moving features by bulk edit on the feature list screen is still painful (they have to recreate all of the phase/milestone dependencies and tasks).