[Toaster]

The first step will be a "learning" computer.
This wouldn`t be a BIO computer but rather a form of AI.
This isn't as far off as some may think.
But to be truely "learning" in the human sence is another matter.

The biggest stumbling block is the definition of learning and how to program a computer to do so.
We carbon based life forms (humans) learn by doing, watching others and making mistakes umongst other things.
Ask a computer which way to turn a door knob to open a door and you might get nothing done unless the program said: "Try one way then the other"
We humans instictively try both ways unless the door is marked which way to turn the handle/knob.
For the computer to "learn", we simply say via programming:
"This device allows access to another area"
"Minimal force via rotation either L>R or R We knock, the computer may simply "try the door".
When a computer can make an "Emotional" decision, then things will proceed at a dizzying rate. Without "intuiton" and other data, the computer is nothing more then task orientated system.
The computer will need to know:
Order of task
type of task
do what on failure
do what on success
error management
cycle repeat
cycle retry
cycle on "X"
abort on "X"
and on and on......
I think you might see where this goes and the hurdles that need to be overcome.
Once these are overcome, the final obsticle would be mans own arrogance.