The idea is to host a network hard drive with large capacity that can be "streamed" to a wifi-enabled handheld device to bypass portable storage demands.
Streaming should work fine for most retro consoles, but starting with PS3/Wii for example, it would be nice if the software asked the user if they want to download locally to avoid wifi speed issues with larger ROM file sizes. A simple pop-up window in the UI could function like Steam where the user chooses a local folder to install the ROM. To go along with the install, there would need to be a method to uninstall and tell ES that "we are using the remote hard drive again for this game".