good call. setting that up, though, requires more expertise than most people can handle. even if they can figure out getting a dynamic dns type client, they have to configure a FTP Server or set up VPN access...both daunting to casual users. then, they have to configure their router's firewall. honestly, i'm even a fan of microsoft's 'to the cloud' concept to at least get people interested in this technology...hopefully they will get a taste and then want to do it right (I'm assuming Microsoft's implementation is general, at best) eventually.
As for cloud storage, this seems like a no-brainer. But I'm with the people who want to keep their files locally, too.
...so, you have some type of 'sync' feature built in for your computer (which, in theory, has enough storage to hold all your files), and the ability to stream to your handhelds and other limited storage devices or for when you are away from home. Or, the option to choose what to sync to a handheld, which could help with bandwidth. It could even require some type of monitor to ensure a purchased file isn't being used concurrently, in two locations to appease the record labels.