I'd definitely get one, but I don't see it happening. If this happens the 5c as it is would have to be discontinued as well... So I honestly don't see them discontinuing two different devices.
Sure you could say they can just keep the 5c the same just add touchID, but I don't think it'll happen ... JMO
We didn't expect them to introduce two new models at once but then the 5S/5C came out, who's to say they won't discontinue two models this time.
I hope they keep the 5S the way it is and just lower the price without adding the plastic. It's an exceptional phone.