The upcoming XCOM: Enemy Unknown has got itself a fancy new preorder system on Steam, rewarding customers with pre purchase rewards. Sorted into three tiers, each offering a different reward, XCOM only unlocks more rewards as more people pre purchase. Tier 1 includes:

Tear 1 Elite Soldier Pack will provide the ultimate tools for soldier customization in XCOM: Enemy Unknown, including:

Classic XCOM Soldier

Players will instantly receive a new recruit in their barracks inspired by the original

X-COM: UFO Defense. The iconic soldier with the blonde, flattop hairstyle will return fully modernized.

Soldier Deco packs

Players can customize their soldier with several aesthetic upgrades to armor suits, including the new Hyperion and Reaper soldier armor kits.

Complete color customization

A variety of colors and tints for all armor sets in the game allow players complete control to customize their squad’s look.

Tier 2 is the above, plus 3 exclusive Team Fortress 2 items:

The Crafty Hair

If you're ever planning on fighting aliens, this is the hair to have.

Area 451

If aliens ever invaded Badlands and used their special alien powers to make all of our heads look like alien heads, this is a scientifically accurate representation of what Pyro would look like.

The Vigilant Pin

This pin proudly states to all that you are at least vaguely aware of the possibility that maybe aliens exist.

And finally Tier 3, which gives you a free copy of Civilization V, plus everything else previous rewards include!

If enough people preorder this game, then all this is yours. If not, then presumably it will all go up as downloadable content later anyway. It seems to me that they should have included Tier 1 in the game from the get go and then made Tier 2 and 3 the preorder bonuses. Anyway, if you were getting this game, now you have more to look forward to. If enough people preorder that is.