Update October 25, 2013:
We've got a fairly substantial update for you all today! You can see the changelist on our forums
or you can read below for part of the changelist (the list is so big it exceeded the maximum character limit for this announcement):
-Added new "Strike" game mode which is a reinforcement based cache hunt mode, where one team must defend 4-5 weapon caches (depending on player count) against the other team, which must blow them all up before the round ends. Teams get unlimited reinforcements until there is only 1 cache remaining, at which point the defending team no longer has any reinforcements. Mode is supported by District, Heights, Market, Buhriz and Ministry.
-Added new "Search and Destroy" game mode which is a single life mode with 1-2 weapon caches (depending on player count) where the attacking team must destroy one to win. Mode is supported by Contact, District, Heights, Market, Buhriz and Ministry.
-Added C4 back into the game. C4 costs 4 supply and is the best way to destroy a weapons cache, although multiple frag grenades work too. You can get two C4s if you have a chest carrier. The Specialist role now has C4 by default.
-New particle FX for explosions, muzzle flashes, car fires, smoke, impacts, and more.
-New HUD elements implemented (e.g. relative team colors, objective icons and scoreboard).
-Added new toggle Walk as the default walk in the game. If you preferred the old way of holding the Walk key down, you can change it back in Game Options.
-Added the ability for destructible weapon caches to be used as objectives in Checkpoint and/or Push (currently this is only implemented in siege_coop on Checkpoint).
-Visually updated maps: Heights, District and Market.
-Greatly improved animation movement blending so players will now fully extend themselves when moving instead of appearing rigid like before.
-Spectator reinforcement information is now a little bit more descriptive, depending on the game mode. No longer says "Waiting for reinforcements..." when there are no reinforcements left.
-Improved the volume levels of footsteps.
-Tweaked shotgun damage.
-Kit selection now automatically comes up, and must be accepted before you can spawn for the first time (should be less confusing for new players).
-Buying weapons, upgrades or gear won't give you the items as you buy them. Instead, it will give you the items when you close the menu (saves some bandwidth).
-The VIP is now displayed as VIP in the kill feed.
-The VIP can now see their teammates everywhere in the map.
-In VIP and S&D your team receives a supply token if you win.
-In VIP the escorting team now loses if time runs out.
-Improved Coop bot count scaling based on how many people are playing.
-Added console variable mp_coop_min_bots so the server can specify the minimum amount of bots on a server with 1 human player in Coop (it will scale up depending on what maxplayers is set to).
-Improved Outpost mode so the bots find players better and the wave times are more appropriate.
-Fixed a major damage bug where players were being spawn protected for 30 seconds after they spawned, even if they left their spawn zone. Now players still get the spawn protection in certain modes, but it goes away as soon as they exit the spawn zone.
-Fixed switch teams functionality (as well as mp_switchteamseachround) so it no longer crashes the server if there are a lot of players and team scores properly switch.
-Fixed fall damage
C4 is back! Better be careful.. We will see ya on the servers!