I completely undersand why William Lane Craig was frustrated. Maudlin showed up to a discussion on God and Cosmology to present a paper which he provided to other participants for response. That morning he decided that instead of presenting the paper, he felt he needed to instead talk about why the question of God and Cosmology isn't useful (who cares about Boltzmann Brains) because even if God exists it doesn't have any meaning (morally, purposefully, etc.). He even announced this at the beginning of his talk saying he was about to give a sermon.
The questions the forum hoped to address are those that require thoughtful inquiry, not on-the-spot responses. Showing up and giving a speech at best tangential to the topic and wholly different from the intended discussion removes nearly any chance of truly insightful discussion (as no one had any time to prepare, study, critique or question Maudlin's thoughts).
Finally, I am growing sick and tired of hearing guys like Maudlin and Rosenberg and Krauss show up to debates and discussions and then complain about the format as not being useful or valuable. If it isn't, then just don't show up. Don't waste your audiences time telling them they are wasting their time listening to you give them that information in the format that you consider to be a waste of time.
On a final note, did we seriously have to hear th Euthyphro Dillema again? Seriously, this has been asked and answered for centuries... http://en.wikipedia.org/wiki/Euthyphro_dilemma#False_dilemma_response
Whether you think the answer is credible or not is one thing, but to present it as if there is no articulate response from the theist is simply false.