minimal BOM (minus small passives):

 - Core
    - SoC
    - power management/regulator IC for SoC
    - RAM
    - Onboard FLASH
    - FRAM chip (SPI? SDIO?)
 - WiFi
    - regulator/powermanagement
    - WiFi baseband
    - WiFi radio
    - WiFi antenna connector
 - 802.15.4 
    - regulator/powermanagement
    - all-in-one chip
 - ethernet
    - ethernet switch chip and/or PHY chips
    - ethernet drivers (for long cable runs)
    - connectors with LEDs
 - power
    - 5/12v regulator, ~1amp
    - power connector
    - reverse voltage diode
 - SD connector
 - status LEDs and drivers (PWM from SoC?)
 - reset button
 - power switch

tests:

 - 10/100/1000 half/full duplex fallbacks
 - 100m ethernet cable run (full bandwidth)
 - high/low temperature reliability
 - wireless range and bandwidth
 - network latency
 - network throughput
 - "fair" contention management
 - WPA2 actually working
 - total bulk data bandwidth
 - max small packets/second
 - dhcp server performance