Marissa Mayer has announced that the Yahoo purchase of Tumblr has now passed regulatory approval procedures and is now complete. Yahoo has agreed to acquire Tumblr last month for $1.1 billion in a cash deal. Mayer also reassured users of the platform:
As promised, Tumblr will continue to operate as a separate business, led by David Karp as CEO. Their product roadmap, their team, and tone will all remain the same as will their mission to empower creators and curators alike to do what they love best: create.
Source: Yahoo Tumblr blog