I'm coming way late to this conversation but I have always wanted a Panasonic Toughbook quality device that could do the following:
- RUN or at least charge off 12v DC current (preferably without an external power adapter but I may be dreaming)
- 9" screen size capable of popular resolutions for easier web browsing
- 10+ battery life (Preference on something easy to replace like AA batteries)
- Linux OS so I don't have to pay and pay and pay
- use E Ink brand electronic paper displays (256 level grayscale is all I need)
- Possibly a swiveling touchscreen
- Solid State Drive (32GB+ would be nice)
- 4+ USB powered ports (at least three not right next to each other)
- 3/4 sized keyboard
- built in GPS receiver
- headphone jack
- sound card that can support Phase Shift Keying, 31 Baud for HAM communication
- fanless
- wi/fi chip with the option of digital cellular network communication module
- built in card reader
- sound in capability
- built in surge surpression (no not EMP but dirty power resistant power supply)
- weather resistant
- capable of standing up to field abuse (I love the Panasonic Toughbooks but they are way more than I need, not to mention the weight!)
- Top notch power saving
Don't need: I understand some would be necessary for retail sales
- color screen
- back-lighting for screen
- speakers (at least audio off by default)
- camera/web cam
- optical drive
- Pcmcia or EVDO drive
- loud fan
- look at me I'm cool, shiny brushed aluminum exterior (no I am not an Apple hater)
In fact I almost want something like the old Apple Newton.

Form factor is spot on, built in modem, used AA batteries, no external power brick, touch screen worked great but also had an attached screen cover, and was great for low power usage as it was grayscale video only. Add SSD, some USB ports and capability to run off 12v DC current and I would buy them like crazy. Though I think this technology was pre PDF and that would be necessary.