Joss Whedon was a spaz; entertaining, but nevertheless a spaz. I don't care enough to transcribe everything he said, which was mostly bitterness at Firefly (with optimism for the future), closure over Buffy, and dodging of questions about future story arcs. Luckily, Rebecca Salek did good job of transcribing the Q&A session, which you can find in this Newsarama thread.