By including ".github.com" in the name, the project is, to me, trying to parade itself as being part of github or affiliated in some way. They're using github's name as an appeal to authority. It's a neat project, but needs a better name.
Yeah, not particularly. Most of the ones I've seen (again, casual Github user) are not trying to use .github.com in the name of their site (regardless of address). Here, the project is named, "giving.github.com," implying Github affiliation. http://square.github.com/cubism is clearly branded as Square, not square.github.com. There's a big difference.
