I was sold on it at first, but I'm now firmly in the "fake" camp. While it's impressive, all you would need to do is have an adjusted for the rumors mock lineup ready to go. The two images used in the poster come straight from the website. There is a misspelled band on the poster and a few inconsistencies with the bold/not bold font.
Plus, aside from Paul Simon performing Graceland, there isn't really anything on the lineup that people haven't been guessing. Bonnaroo always has a few tricks up their sleeves when it comes to a lineup.
I'm gonna start trying to push its credibility by claiming i saw it on the bonnaroo.com site when they updated it too. I suggest others do the same if we want to see music websites embarrass themselves.