Thanks for inquiring Aspose.Slides.
I have observed the requirement shared and regret to share that at present the only option available is clone Shape class instances in PPT. Unfortunately, neither the ShapeEx cannot be converted to Shape nor it can be copied in shape. However, we are working in this direction and hopefully during Q4 of 2013, we will launch the unified Aspose.Slides API for PPT and PPTX presentations. The said releases will included support for copying PPTX ShapeEx class as well.