This is the page about Project Patchstick, a 100% legal way to open up the ATV for hacking without having to open the case.
- Build our own Darwin kernel that boots on the ATV
- Build our own sshd (probably dropbear)
- Install sshd on the ATV, enable it
- add more hacks (ericIII's ATVFiles comes to mind)
- make it work from a (small) USB stick