Leaked photos have revealed that there will be a content creator for GTA Online, a feature Rockstar suggested they might implement. One player managed to access this feature and posted screenshots to the internet of his ability to change settings for a mission, such as the type of mission, inventory information, the number of players, and more. Another player uploaded a video of the mission creator.
At this point, it seems as though the feature is buggy, and players cannot used it successfully. However, now that its existence is known, it seems like only a matter of time before it is polished and officially released. A mission creation feature could prove to be the savior for GTA Online, which has had more than its share of issues and controversies.