1. For a Linux user, you can already build such a system yourself quite trivially by streaming from /dev/urandom, mapping to cardinal directions and simulating a random walk on the keyboard.
2. It doesn't actually replace an email autoresponder. Most people I know will put things like their return date in the auto-response.
3. It does not seem very "scalable" or income-generating. I know this is premature at this point, but it seems that down the road this may require a lot of horses.