The Nano Edition, which will retail for £119.99 / $149.99 will include an 11" statue, a high quality art-book and a specially modelled backpack to house the goods. Obviously, you'll also get a copy of the game housed in a steel case.
The Limited Edition, which will be cheaper, includes all of the above minus the 11" statue. The pack's due date an date with the game. Crytek warns that the Nano Edition will be sold in extremely limited numbers, so you're best getting your pre-order in soon if you want it.