I don't think internal storage would be a benefit here. After all, there's a reason for the name...Transporter. Internal storage adds noise, heat, and maintenance issues. Once people realize how cheap and easy it is to keep ones music on a central server, or on a standalone NAS device, they'll see why it's only the transporter and not the storage. To have yet another device in the house which needs backing up, software upgrades, etc. is not necessary. For $150, you can throw a huge, reliable hard disk into your home computer, and, voila, your music server is done. Want to upgrade that storage? It's as easy as typing a few keystokes on Newegg and it shows up at your door; nothing proprietary or expensive to deal with. There's a very neat division between the device on which you rip and store your music (and all your other files as well), and the devices on which you listen to your music.
What the Transporter needs to have for this price is look, feel, and SOUND SOUND SOUND. It should compete with the best CD players when used as a transport to an outboard DAC, without the need for mods or replacement power supplies. Even better would be a Transporter with such a good internal DAC that even those with good ears and high-end systems won't want to add one, though that remains to be seen.