I agree with all of those sentiments. At the same time, I prefer the idea of presenting previous open source work instead of having a group of potential employ

I agree with all of those sentiments. At the same time, I prefer the idea of presenting previous open source work instead of having a group of potential employers agree on a project that they can all judge. One benefit is that the work is less arbitrary, potentially useful for others. Another is it's more likely to be unique than an assignment is. Finally, do I want to work for any of those other employers? Applying to a group that way would seem odd to me; part of me thinks that choosing companies is important, but another thinks that there's some chance that that's just because I haven't tried it. Which, of course, leads me to agree that the OP is great as an experiment - it might well be a better solution in many cases. The fact that, in the OP, it's opt-in is a big deal as well. Though I'm still very skeptical of take-home interviews in general.