This time round collectors edition is available as both digital and boxed versions. You can pay an extra £10 and a standard edition is upgraded to the digital version which gets you all of the in game items (Or you can preorder the digital deluxe for £39.99) and avoid missing out on late deliveries altogether. You do lose out of the boxed items but for a lot of people I bet this is something they will go for.
I am still waiting for the boxed set though as I have all (except Vanilla) and I like completeness :)
Note to those not interested in a box: Blizzard sell the digital copies (including digital collector edition) cheaper than here. I bought Cata from Amazon cos it was £17.92 - I guess they got stung by an immense order intake? (Or got shot down cos indigo blowfish were crap at posting them). Anyhoo, if amazon don't reduce their prices, I'll buy direct from Blizz and be ready at midnight! (if i were to stay up until then, which I don't plan to do)
I play on the US version of WoW. If I buy this will I be able to use it on my US account and still be playing on the US servers no problem? Or do I have to do digital / buy from the US. I used to live in New Zealand which is why I am on the US servers.