A brigade of new details on Team Fortress 2's Mann vs Machine update reported for duty sometime last night (after I finally stopped F5ing the page and left the office.) In case you missed our reveal, the new mode will bring a co-op vs AI horde mode to Valve's free to play shooter. The Day 2 update details what you can spend all of the cash you get from blowing up robots on.
Firstly, a new action slot item is being added: the Mann Co. Canteen. These military-grade receptacles can be filled with three doses of one of several different effects: Temporary invincibility, temporary 100% critical chance, instant ammo refill (I don't know how drinking from a canteen accomplishes this, and I don't want to know), instant teleport to the respawn point, and instant building upgrades for engineers.
In addition, you'll be able to throw down your cash at an Upgrade Station throughout the course of the match to beef up your primary weapon. These upgrades won't transfer into future matches or into multiplayer, however, adding a MOBA-like progression to each bout. The example of the Demoman's trusty grenade launcher was given, which can improve in the areas of Damage, Ammo Capacity, Firing Speed, Projectile Speed, Reload Speed, Clip Size, and Health On Kill. Each category has three or four progressively more expensive levels.
Powers that be permitting, Mann vs Machine should go live sometime today.