Steve- I think you win the prize for "customized personal interpretation of ambiguous language". You're right, the code does not specifically prohibit what you want to do, but there's not an electrician in the country who doesn't read 210.52(B)(2) to mean that the minimum 2 small appliance circuits are to serve 120v receptacles on the kitchen counter top and nothing else. In fact I think that the people who wrote it meant that too.
There's a lot of off topic stuff in the replies, some of which makes sense but the thing I see in your question that shoots this down, even if 210 doesn't is the idea that somehow two 12/2 romex are parallel conductors in the same raceway. I think you knew the answer to that before you asked. What would the schematic for that arrangement look like? I'm thinking that they don't even run to the same box. Would you reroute them to a single box, put the coffee pot plug on the circuit first and then split them out? And that would be easier than a new circuit? Curious.
