Yahoo has officially announced the all-cash acquisition of blogging site Tumblr, picking up the six-year-old company for a cool $1.1 billion.

The move, which was telegraphed by the major tech sources over the weekend, comes as no real surprise, and ReadWrite’s Owen Thomas already has insights on the potential directions for the deal. But details are coming out this morning on what -initially – Yahoo has planned.

(See also Buying Tumblr Will Leave Yahoo With The Same Old Identity Crisis.)

Rather interestingly, Yahoo will be moving its official blog to Tumblr. And in the very first blog post, right out of the gate, Yahoo explicitly affirms the question that was on everyone’s lips this weekend when the news was first leaked:

“I’m delighted to announce that we’ve reached an agreement to acquire Tumblr!,” wrote Yahoo CEO Marissa Mayer, “We promise not to screw it up.”

Mayer’s post was the epitome of how the two content companies should be able to work together.

“In terms of working together, Tumblr can deploy Yahoo!’s personalization technology and search infrastructure to help its users discover creators, bloggers, and content they’ll love. In turn, Tumblr brings 50 billion blog posts (and 75 million more arriving each day) to Yahoo!’s media network and search experiences. The two companies will also work together to create advertising opportunities that are seamless and enhance user experience,” Mayer continued.

Given the type of content produced in some of those 50 billion daily blog posts on Tumblr, it will be very interesting to see how that seamless mesh of advertising opportunities will work, since advertisers are sure to be all over NSFW blog posts.

Image courtesy of Yahoo.