If you are a fan of Team Fortress 2 items and/or free video games, you’re in luck. The folks over at Steam are running a PRE-PURCHASE REWARDS PROGRAM, and it works like this: If enough people pre-order XCOM: Enemy Unknown , they will unlock 3 exclusive XCOM-themed items in Team Fortress 2. If even more people pre-order, they will unlock a free copy of Firaxis’s other big title, Civilization V (and yes, you can gift it to a friend if you already own it). These are both in addition to the Elite Soldier Pack which already unlocks when the game ships just for pre-ordering.
Update: I direct copied that block of text from the link, and they have since removed the bold sentence. This is troubling.
Update #2: From Greg later in this thread:
Guys, we're at 10% to tier 1 after only an hour on sale. :P
I just got word from the team that I can personally guarantee that all Steam pre-orders will get the Elite Soldier Pack. If by some strange horrible anti-miracle we don't reach tier 1, we'll be sure to get the ESP to all of you anyway.