It's been done (BWO). The information displayed never had much of anything to do with how far along the project actually was.
I'm not bashing BWO, mind you. Nobody's getting paid for any of this, and thus nobody is working on a regular schedule. Ninety percent of the work could be done, and the remaining ten percent could take just as long. For that reason, it isn't really meaningful to try to reduce the progress to a bar graph. "When it's done" is the only accurate answer you'll get out of a project, and if one tells you otherwise they're very probably wrong.
Again, nothing wrong with that. Everything here is volunteer work, so nobody has any right to complain about, well, anything.
Or go into the BWO forums and post a review of Duke Nukem Forever.