The Doc gave a rapidfire (and garbled technobabble as usual) explanation of how the cells are split and mixed (more like meiosis rather than mitosis) which means she was not technically a clone. Thought 'the source' was a bit silly and acted almost as quick as Anadin.
Enjoyed it though
I also thought Cobb was Arthur from Excalibur but wasn't certain.
A spin-off possibility? Undoubtedly.