The reason why we did this is twofold. First of all it's a joke based on the type of humour known from Chuck's Testa ad (http://www.youtube.com/watch?feature=player_embedded&v=L..., chances are he didn't mean to be humorous). When your specs fail, the formatter at first tells you that they pass, just to reveal the truth a second later. This was meant as a joke so we didn't attach any screenshots on purpose, as you don't usually explain a joke before telling it. We now understand this put many people off, and we probably could have done better.
ChuckTestar is, however, something more than that. If you're a Ruby developer chances are that at some point you may find the ability to use custom RSpec formatters useful. What we show with the open source code is how to overwrite default formatter's behaviour, how to add Growl Notifications, how to make your machine tell you (i.e. speak out loud) whether your tests pass or fail. We solve the problem of supporting both OSX and Linux. That's a bunch of really useful things packed into this small gem.
There's also a related blog post that I wrote explaining all this in more detail: http://applicake.com/blog/index.php/2011/11/15/how-to-write-....
Take a look at the announcement post for rspec-fuuu (http://sjackson.net/2011/08/30/rspec-fuuu.html). It says "Hey, it turns 'FFFF' into what you're really thinking: 'FUUU'". I understand exactly what the gem gets me, and why I should be amused. Your gem provides none of that. No examples, not even a sentence explaining how the output format changes. Even your lengthy blog post (which does a good job of explaining how to set up a custom formatter) tells me nothing at all about what your gem actually does. It's a bad sell.
Amazing.