The Civilization 5 patch 1.0.1.674 brings the new Steam Workshop to Civilization 5. The patch adds font icon and unit art moddability to Civ5. It also disables the diplomacy modifiers for trying to win the same way, which we already know from the Civ5 addon Gods and Kings. Here is the full list of changes:

[MODDING]

• Steam Workshop enabled.
• DLL swapping is now possible in-game.
• Updated mod browser to utilize Steam Workshop.
• Font Icons are now moddable.
• Unit art is now fully moddable.
• Mods are now activated the moment you click "Next" on the mods browser rather than when you click "Single Player."

[ADVISORS & TUTORIALS]

• Improved the queuing and prioritization of advisor pop-ups.
• Unique advisor portraits per era now show up for the advisor counsel screens and advisor info screens.
• Adjusted advisor levels down a bit so that experienced users won't see so many tutorials.
• Fixed several issues with the Tutorials.
• When selecting "Learn as you play," all tutorial messages are now enabled despite having your options set to "No Advisors."

[MULTIPLAYER]

• When switching players in hotseat, have the new players existing notifications rebroadcast to them. This allows the player to see non-expired notifications such as deal proposals.
• Fix Diplomacy Deals in Hotseat.
• Add a few multiplayer error messages to let the player know what went wrong (disconnects, gets booted, etc.).
• Add invite button to in-game view. (This brings up the Steam Invite list, which is different from the Shift-TAB overlay).

[UI]

• Main Menu now contains an option to activate/deactivate specific DLCs.
• Quick combat and Quick Movement options are now part of the Options menu and can be changed during gameplay.
• Options menu now contains "Skip intro video."
• New Loading screens have been implemented.
• Diplomacy: Disabled modifiers for trying to win the same way.
• Diplomacy: Layout changes to diplo modifiers for better readability and more information.
• Mods and DLC used in a game are now stored in the Hall of Fame database (Only games which match currently active DLC are displayed in the Hall of Fame).
• The "Time Spent" message now displays in the saved replays.
• Load Replay Menu now defaults to "Sort by Last Modified."
• Added a "Retire" button to the game menu.

[GENERAL]

• In some cases, previous saves may not work correctly after updating.
• Several text bugs fixed (in all languages).
• Prevent escape from being used when a leader requests a luxury resource from you.
• Social policies may not be unlocked unless the player has founded at least 1 city.