No, I wasn't expecting any of them to function as a USB DAC. Just something simple with FM radio and an auxiliarly input switch that would do little more than volume control of the input.
I did a quick check on Crutchfield. Apparently there are such beasts, or something similar to what I'm looking for, labeled "digital media receivers". It's fairly slim pickings, with many of them designed to work closely with Apple iPods. They have software to navigate the music, iPod docks or cables with the necessary connectors, even pockets behind the faceplate where you stash the iPod after plugging it in. The ones that can work with USB attached storage are interesting, but from what I've seen, the software is extremely limited and I want to navigate the library on the touchscreen computer.
I'll probably just end up with a standard receiver with single-CD player that will never be used.