Update - 4 October: Now with 34-minute extract highlighting the NASA social media presentation (scroll down a bit...)
At last, here's that replay you've all been waiting for. It's 4 hours long - so bring snacks!
Bite-sized edit (update 4 Oct 2011)
The nice folks over at NASATweet have prepared a relatively bite-sized 34-minute extract that includes the (excellent!) NASA social media presentation by Beth Beck and Stephanie Schierholz, which you can watch below. Thanks to @jonverve for the nice work.