I'd definitely give it a try. I don't know whether it would fit HN as nicely as it does Reddit, but there is just one way to find out, isn't it? :)

edit - I also wonder how it would evolve on HN. I could imagine using it here not for tipping, but for crowdfunding of sorts. With so many vcs reading this group, I'd expect people throwing 1-2BTC at a time at good ideas/ShowHNs to support some of the entrepreneurs.