It’s been reported all month that Twitter was acquiring TweetDeck. This week, CNN reported that the papers had been signed, but there was stilll no official word from Twitter or TweetDeck. Until now.

In a post on the Twitter Blog, CEO Dick Costolo writes:

In early 2008, a London-based programmer named Iain Dodsworth began thinking about how to organize everything happening on Twitter. His answer was TweetDeck, a groundbreaking dashboard for monitoring what people are saying in real-time. Today, we’re pleased to announce that the TweetDeck team has joined Twitter.

TweetDeck is a great example of a third-party developer that designed tools for the incredibly important audience of Twitter power-users and, in turn, created value for the network as a whole. As Iain’s journey suggests, there is significant opportunity for developers who deliver insights that foster a more engaged Twitter user base.

A post from Dodsworth on the TweetDeck Blog indicates that TweetDeck will be integrated into Twitter’s official platfrom. Dodsworth writes:

The past three years have been an epic journey, with many highs and lows, accompanied by the constant thrill of never really knowing what to expect next. We’ve grown from one team member and a single user, to a team of fifteen and a user-base of millions. The reason for this growth is simple – our unwavering focus on providing high-quality tools and services for the Twitter-centric power-user. This has always been our core audience – the most active, influential and valuable users of Twitter and social media in general. Quality over quantity.

Change may well be inevitable, but we remain the same team, staying in London, with the same focus and products, and now with the support and resources to allow us to grow and take on even bigger challenges.

In a recent talk at Columbia University, Jack Dorsey discussed TweetDeck, shortly after rejoining day-to-day operations at the company. “TweetDeck is a very interesting client, because it presents a view that no other client in the world presents, which is this multicolumn, massive amounts of information in one pane,” he is quoted as saying. “And people really, really enjoy that. But I think that’s maybe five percent of the Twitter population. That five percent of the Twitter population are some of the most high-value publishers that we have, and they’re using the service at extreme velocity. So of course we have to pay attention to that, and I’m not saying we need to rid ourselves of interfaces like that. We have to embrace them.”

It would appear that all kinds of Twitter users will be embracing it now.

The deal is believed to have been done for $40 million in cash and stock.