Ya NanoNote feature requests
Things I think are in the realm of reality:
OLED display for lower power-consumption and better outdoor visibility.
More screen per lid (less of a huge border around the display).
More RAM (64M~256M).
A second SDIO slot.
Built in 802.14.5 "atben" with an internal antenna, and external antenna connector.
Optionally expandable battery.
Non-glossy display finish (hooray, glare).
Contention with other suggestions:
No Bluetooth/WiFi/3G built in, as we're trying to stay copyleft and steer clear of patent encumbered hardware. (end-users can use second SDIO slot for this if need be)
Fantasy:
Perhaps (big perhaps, as OLED is expensive) a larger formfactor (like the Jornada 720).
A second CPU, or a single dual-core cpu. (preferably still MIPS-compatible).