although a nice idea in theory I doubt it will ever get anywhere like you would like it too.
We tried torrents on upps with pip and it just never catches on, people jump in and seed at first and then move on to something else and forget all about it.
A better solution is for someone with a good hosting site account on dev-host, android file host, or goo.im etc upload it. That way its there for all to download even after you all have moved on to other things.