Eh?
That's odd... I purchased a proper Collector's Edition pre-order box from HMV months ago for £9.99 (which will be deducted from my final purchase of the CE) and that already had the codes inside it.
Or have HMV oversold their pre-orders once these special boxes ran out and they're now in the sticky stuff? Think I might camp outside my HMV on Thursday morning to make sure I get mine!