It sounds scary that Apple's applications would be Leopard only. That would mean the OS has changed a lot and most of my current applications might break. I would definitely wait a lot longer before upgrading.
There are some people that don't have an ipod or maybe a nano. I guess they could it onto a DVD and bring it over to the friend's place.
That NAS RAID thing sounds like something I would use to threaten my kid when she watched too much TV - turn off the TV or the NAS RAID will get you.
Because the physical media works on all my DVD players including the one my kid watches in the car on treks. The physical media also works on all my friends' DVD players when we the kids get together for play dates.
Also, the download is gonna be backed up to DVD to free up hard disk space so it ends up on DVD anyway so I just as soon get in on DVD in the first place.