The key points:
- Maxis have built the game with a mods directory to drop your mods into, so you don’t have to mess about with game files to add custom content.
- They will be posting a guide on decoding the structure of their files, to help the community to build modding tools.
- There will be features that will make it easier to add, remove and manage custom content.
- Maxis will communicate with the community to reduce the chances that your custom content will be affected when they update the game.
- There will be a dedicated section of the official forums to discuss modding the game and custom content creation.
- Custom content will not pack with Sims, lots, etc, so you don’t need to worry about accidentally downloading lots of content you don’t want.
Read the full article here: http://www.thesims.com/news/mod-mod-world