Green Man Gaming has XCOM: The Bureau available for pre-order right now for $44.99 (save 10% off). You also will receive a choice of $8 cash back or $12 in GMG credit to be used towards a future purchase.
In addition the more people that pre-order the more bonuses that will unlock. The first bonus already unlocked is the Codebreakers DLC for the game. At the second level you’ll receive a free copy of Spec Ops: The Line. At the third level you’ll receive a free XCOM Ultimate Bundle, featuring XCOM:Enemy Unknown, Elite Soldier DLC,Slingshot DLC and 4x XCOM Classics titles including UFO Defence, Terror from the Deep, Apocalypse and Enforce.
This is a Steamworks game and requires a free Steam account in order to play upon release. Prices on GMG are in US dollars and exclude tax.