I agree with the analogy, but hesitate to call it a test bed.  I can see Bitcoin being used for large transaction amounts,  while everyday purchases being made with Litecoin.  To me, it's silly to buy a coffee with bitcoin and the long transaction time.  I wonder if the two might not be tied together at some point.  Sort of like a meter is to a kilometer or other similar (times 10, 100, etc) relationship.