When Bethesda first detailed the Creation Kit for Fallout 4, they said that the modding tool would first release on the PC in "early" 2016, followed by a release on the Xbox One, then the PlayStation 4 as a 'lite' version where players won't be able to create mods, but access them. The Creation Kit will be the tool that allows modders to share their creations with one another, across all platforms.
According to Bethesda, details on the Creation Kit will be coming soon.
@Godly_shit1 we’ll be sharing more details soon. stay tuned.
— Fallout (@Fallout) January 25, 2016
Hopeful thinking tells us that Bethesda will be following through with their early 2016 promise to release the Creation Kit with a tease like that.
It's likely that the Creation Kit will be released similarly to the way the first update for the game was released. It will first be available on the PC as a beta test until the developers have ironed out most of the issues, then it will release on PC. Once PC players bear the brunt of the issues, modifications made in the Creation Kit will be made available to Xbox One and PS4 owners.
Hopefully Bethesda's version of "soon" means later this week.