There's a good video on the official ITV Corrie site (sorry, overseas fans, I know you can't view these) with some secrets from behind-the-scenes at the Coronation Street live episode.
There's an interview with Producer Phil Collinson in which he calls the live episode a 'live disaster movie'. Corrie writer Jan McVerry talks about writing the live episode script and behind-the-scenes secrets from wardrobe, set dressers and more. Well worth a look.
Watch the video here.