Ending (possible spoilers)
I always saw it going one of two ways.
Either Deb and Grayson were the end game, star crossed lovers and soul mates looking for each other and unable to be separated as two sides of the same coin.
Or
Deb would have grown so much as Jane that she wasn't the same person anymore, and would no longer be quite the right fit for Grayson.
Honestly, I think that option two would have been been much more compelling. I don't at all believe in soulmates so option one rang a little hallow for me.
Thoughts?