Heh, can't wait for the day we get clones of modern systems.
The cycle seems to go like this:
1. System is cloned for first time, bad compatibility
2. Clone goes through several changes, compatibility gets better
3. Clone technology gets small enough to make a portable, but with problems
4. Problems are fixed, clone keeps getting smaller and smaller
Really, the only limit for how small a clone system can be is the media it uses.