(This is not meant to sound negative. I am truly excited to see it, interested to see what the YC network can bring to it, and very curious about the investment thinking behind it.)
I could see this being a good way to help new non-profits get over the initial hump of raising awareness, getting administrative issues sorted out and so on. Certainly a service worth more than just the money provided.
Hopefully it'll quickly join the ranks of the larger crowdfunding non-for-profits like Kiva.org, Donorschoose, etc...
The model of charityfund-operationsfunding separation is quite enticing. This kind of transparency fosters trust. If they ask for donations on the side to keep their operations running, by golly they've got access to my wallet alright.