So I got my little linux router all fixed up and connected to the roomba. I compiled a little test program to send some commands to the roomba to make it move, it worked!
Now I went on to power the router via the SCI port on the roomba. From what I have read the power is essentially a tap directly off the battery. So I connected it up and it worked, at first...
Shortly after connecting it the roomba started making the uh-oh sound, over and over again; :( So I powered it off and back on with everything disconnected and it kept making the same sound; plugged it in to charge; same sound.
The only way that I could get it to stop making sad noised was to do the battery reset procedure.
Starting to work on a plan-B for networking the roomba; going with a simple bluetooth serial bridge.