I had missed an important point on my intial read-thru:

One hour of help of any kind given to another member earns you one time credit. Your time credit is exchangeable for an hour of help from any member in the community. It's all about reciprocity.

Before I had noticed that, I wondered what differentiates time banking from any other currency? While there are details that would differ even it wasn't time-backed, as soon as you start weighting the value of the service per unit time, you lose a lot of what makes this fundamentally different. Having said that, I don't know if it will succeed, but it's certainly interesting and I'm inclined to root for it.