I agree that the project is done in good faith and is a completely worthwhile project. See my original comment that started this thread.
I think the proper way of attribution would be a link (or message) in the footer or, at the very least, on the about page. Maybe I'm being pedantic, but if I need to search for the attribution by going to the developers blog or viewing the source code, I don't think that's enough.
This is beside the point, because I agree that the other forms /are/ attribution, but I don't consider the creative commons link a form of attribution at all.