I don't think you can gain any information from the orders in the order book because a large portion of the orders (probably the majority) are market orders and never show up in the order book. In addition, the orders in the order book are not binding and they don't expire, so it might show some kind of sentiment of some unknown age, at best.
Thanks for that - I posted my reply before I should have read yours.
They're good points - things that I didn't consider.
I would imagine though that if a significant difference existed between the two close to the current market price (ie within a dollar or two) then this might put some pressure on buyers to rethink their bid price.
Dunno.