That's what we've been jokingly discussing since we got a levy on CD/DVD media, and now we also get that levy on external HDDs and USB-drives here in Sweden. Either way, a levy on storage-media is not and never was the answer to anything, don't know how it can even be considered. One of the arguments for this new levy on external HDDs was:
"It's primary function is for private copying"
which is just ludicrous...
Most IP-PVRs can record one stream and play another, but can't access a 3rd unless you get a second box due to the limitations of the HDD. The ISP I used to work for allows 5 multicast streams on a LAN connection, more than that any you get kinda cramped broadband speeds, even on 100+.