Preordering the collection from Zavvi gets you the following bonuses:
* Steelbook packaging * A copy of Metal Gear Solid 4: Guns of the Patriots * A PSN code to download the first Metal Gear Solid game * Some limited edition art cards
Only 4000 copies are available and individually numbered. This preorder is only available for the PlayStation 3 version of the HD Collection, since MGS4 was never released for the Xbox 360.