FROM STEAM NEWS (Source):
The latest Team Fortress 2 patch has dropped! Here’s a quick analysis of the changes:
Added the Mann-conomy. This covers a few new elements to the game. First, they’ve added a brand new in-game catalog that allows you to use your “Steam Wallet” to purchase items. This is a novel idea and makes financial sense considering how long Valve has been supporting this game. Note that the Steam Wallet encompasses all of Steam and not just Team Fortress 2. This is similar to Microsoft Points for Xbox, except Valve uses real money.
Next is the implementation of player-to-player trading. This allows you to trade or gift items you’ve found or crafted to another player. Pretty neat addition and about time. They’ve been talking about it for ages. Also note that at the moment you CANNOT trade or craft purchase items.
Item customization is another step in adding more personalization to your character. Certain items, and I believe this just applies to purchase items, can be renamed and colored differently. Kind of a cool idea, but a few in the forums mentioned how this has “ruined” the art-style. I suppose time will tell.
Added new auto-team-scramble system. I have a feeling this change is going to be a hate-love relationship. On one hand scrambling teams is a great feature because it balances the game and ensures a fair match, but how annoying is this going to be for friends who want to play together. Granted servers will need to enable this, but I have a feeling a decent number will since people bitch about unfair teams all the time.
Server Browser Tweaks: This will require some testing, so I’ll hit up an update once I get a chance to play, but it sounds like there might be some serious potential. Server browsing for the most part hasn’t changed a hell of a lot since even Counter-Strike, so updating the interaction, interface, etc. would be a breath of fresh air.
The official MANN-conomy update page
Helpful resource for understanding the new update: MANN-conomy FAQ