Stop killing each other, start killing the most dangerous enemy of all: robots!
It's been teased at for years now. Notes in the backgrounds of levels pointing to something sinister, something less than human. But seriously, there's going to be fucking robots in Team Fortress 2 and you can and will be fighting them, regardless of whether you're on BLU or RED. Mann vs. Machine also introduces a huge new game mode in the game; for the first time ever it's not player vs. player, it's players against the horde, the horde being of mechanized nature during this outing.
This mode isn't really a surprise, it's been hinted at for a while, but for a guy like me it's more than welcomed. I've probably mentioned it before, but my first game on Steam was Killing Floor and that is one of the more well known co-op titles, along with Valve's own Left 4 Dead franchise of course.
This update is dropping today, and I'm extremely excited about it. It's hard to say what challenges will await, for some of what they've teased, including upgrades to your classes, your weapons, and many other things, make the game fresh and exciting for other players that might be tired of the player on player combat as well.
This probably started with the AI bots that were released in 2010 with the Mac update. The rudimentary programming has probably been honed by both Valve and some of the players, and has probably given birth to at least some aspect of the AI that will be used by the horde in this mode.
It's also nice to see Valve poking some fun at some of the more ... reviled ... player class loadout choices, with some of the bots represented as classes such as the Huntsman and Sydney Sleeper Snipers, the Quick-Fix Medic, and the ever popular Fists of Steel Heavy. There's even the Demoknight, something that many consider a plague on the class. Killing all of these should prove cathartic for some players to say the least, and will be quite entertaining regardless.
Anyways, if you've been thinking of picking up Team Fortress 2 since it went free to play, but you've always been more of a co-op guy, then maybe now you should pick it up and give it a whirl. This might be a chance to get in on the ground floor.