App-V 5.1 is out now. There might be a case where you need to convert old App-V 4.5 or App-V 4.6 applications to new App-V 5.1 format.If there are one or two packages it will be easy to create. But what if suppose there are some 100's of App-V 4.x apps? It will be quite complex and time consuming. 
This powershell script will make this scenario very easy. Just provide the folder where the old packages (App-V 4.5 or App-V 4.6) are kept and run the powershell script. Within some minutes, new App-V 5.1 packages will be created in the output folder.