The purchases will be made with funds in a player's Steam Wallet--now we know why that was added--and players will be able to add any amount they wish to their bankroll. Funds in the Wallet can be used anywhere in Steam to make regular purchases as well.
Item sets with bonuses will also be added for five classes--Soldier, Scout, Pyro, Sniper, and Spy--which will reward collectors and purchasers with additional buffs to their characters.
Players will now be able to trade items, though purchased items will not be tradeable in the short term, and customize others by naming them and changing their color scheme. Players will also be able to gift items to other players.
Community created items, beginning with the Polycount Pack, will also be sold and the creators will see some of the money earned on their item from Valve, though details are still forthcoming on this feature.
There are a lot of rules and policies surrounding the Mann-conomy update, which are all detailed in this FAQ provided by Valve.
Free updates will continue, though microtranscations have officially landed for the game. How do you feel about this update? Let us know in the comments.