Currently, you won't be able to change the material swatches so that they appear in list view or alphabetically in the program. However, one thing you can do is to go to the Documents > Zaxwerks > ProAnimator > Material Swatches folder and delete the _Material Swatches.idx file. Once you do this, the next time you launch ProAnimator, your Material Swatches bin will be sorted in alphabetical order.
Hope this helps. If you have any other questions, please let me know.