Kind of unsurprising, but it looks like Epic is launching a storefront and they're not shy about making it clear that they intend to compete with Steam, at least in terms of getting developers on board:
Epic has published games in the past, obviously, but it looks like they're making this with the express intent of getting other developers/publishers on board.
When You Succeed, We Succeed
We’ve built this store and its economic model so that Epic’s interests are aligned with your interests. Because of the high volume of Fortnite transactions, we can process store payments, serve bandwidth, and support customers very efficiently. From Epic’s 12% store fee, we’ll have a profitable business we’ll grow and reinvest in for years to come!
It's an interesting idea and I hope it has a good UI. I know everyone loves to have everything on Steam but I generally try to buy from publisher's storefronts for stuff like Ubisoft games just to ensure they get max revenue out of it. It'll be curious to see if Steam ever decides to drop their 30% cut.