I'm not sure how I missed this bit of info, but the NES PowerPak Mapper package has been updated to version 1.20, adding something as cool as Famicom Disk System support as well as the ability to play .NSF files.

Also the firmware has been upgraded to version 1.11, but only minor cosmetic changes has been made.

Download the firmware here
http://www.nesworld.com/powerpak/powerpakboot111.zip

Download the mapper pack here
http://www.nesworld.com/powerpak/powerpak120.zip

The copyrighted Famicom Disk System BIOS is of course not supplied by RetroZone, but you should be able to find it elsewhere on the net. Once the BIOS file has been obtained a patch has be to applied to be able to use it with the PowerPak. A download is available here
http://www.nesworld.com/powerpak/fdsbios.ips

An updated version of the PowerPak has also been made available and it can be viewed/downloaded here
http://www.nesworld.com/powerpak/powerpakmanual120.pdf