1) Linux SBC with Python (out of the box)
2) Ethernet with DHCP working (out of the box)
2) Lots of GPIOs
I have a Mini2440, but it came with a Linux with unworkable DHCP. Weird. Oh yes, I can download a toolchain and compile my own kernel and load it up to get DHCP working. Maybe I can even compile and get Python going. If I could spend a week straight working on this, sure I could do it.
Meanwhile I have the SheevaPlug, which does DHCP and Python out of the box, but no easy GPIOs. You can hook it up to an Arduino though. So looks like that will be the answer to my madness.
On the other hand, I may just go Chumby & Arduino.