Allow branching operations to perform parallel actions

It would be extremely useful and increase the power of Phatch enormously if it supported branched processing pipelines, instead of just linear ones. For example this would allow you to create one pipeline which processed a single source image in multiple ways to produce multiple output images - a medium sized and a thumbnail sized version, for instance.
ImageGenius (http://www.pixeldragons.com/Products/ImageGenius/Index.ashx) is an example of an image processing application that allows this and it provides it with much power and flexibility - it would be great if Phatch could acquire this ability.