Twitter has acquired TweetDeck, an Adobe AIR desktop application for Twitter, Facebook, LinkedIn, Google Buzz, Foursquare, and MySpace. The deal was completed yesterday, has been announced today, and the two companies are now in the process of figuring how best to merge as one. Details of the deal were not disclosed, though many believe Twitter paid between $40 and $50 million in cash and stock for the startup.

TweetDeck's team of 15 will be 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. It's not clear if Twitter will remove the other social networks from TweetDeck. It wouldn't surprise us if one or two were dropped, but it would be a bad move to drop them all but Twitter.

The only other acquisition Twitter has made is of the application developer Atebits, on April 11, 2010. Atebits had developed the Twitter client Tweetie for Apple products. The application, now simply called Twitter, is distributed for free as the official Twitter client for the iPhone, iPad, and Mac.

Apart from acquisitions, Twitter has been seriously pushing out updates recently. Just last month, the company announced it had improved search by making it three times faster and also launched a new homepage. Earlier this month, the company started to roll out a new mobile website.

I do not have Twitter for personal use, but I do use it for work. You can follow @TechSpot for news from the site or follow me directly: @EmilProtalinski.

"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," Iain Dodsworth, TweetDeck Founder and CEO, said in a statement. "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."

"This acquisition is an important step forward for us," a Twitter spokesperson said in a statement. "TweetDeck provides brands, publishers, marketers and others with a powerful platform to track all the real-time conversations they care about. In order to support this important constituency, we will continue to invest in the TweetDeck that users know and love. 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."