Until now, players looking to add features to Fallout 4 or make it suit their style a little better have had their work cut out for them. First, they needed to hit a site like the venerable NexusMods. They then had to use a third-party mod manager or do the dirty installation work on their own, with varying degrees of success. Integrating Fallout 4 with the Steam Workshop would make things a lot easier for everyone involved, as happened with Skyrim. There's yet no official word as of yet, though, so it's still possible (but unlikely) that Bethesda will restrict mod delivery to their own store.
Bethesda previously said that consoles would also get mod support, and now Howard has established an accurate timeline for when that will happen. He unsurprisingly says it's "far easier to update and iterate on PC," so it makes sense that plaform will get mod support first, after the first piece of DLC for Fallout 4 hits the market. Mod support for the Xbox One should follow roughly a month afterwards, and PlayStation 4 support is expected to come another month after that.
Now, carry on. Preston Garvey needs you to help another settlement.
UPDATE 2/24/16, 5:35 PM: edited to note there's yet no official word on Steam Workshop support.