In a blog post about the deal, Skype chief Tony Bates said the goal is to "transform communications," though he reiterated that Skype will remain available on non-Microsoft platforms, like Mac, Android, and Apple iOS.

Microsoft and Skype complement one another because both are "disruptive, innovative, software-oriented companies," Bates said in a video message (below). "The world I see in a few years is really one of complete, pervasive video communications, something that's across all parts of your life," he said.

"Skype is a phenomenal product and brand that is loved by hundreds of millions of people around the world," said Microsoft CEO Steve Ballmer. "We look forward to working with the Skype team to create new ways for people to stay connected to family, friends, clients and colleagues — anytime, anywhere."

Bates will now become president of Microsoft's Skype division, reporting to Ballmer. At this point, it will be business as usual, but down the line, Skype will be integrated into a variety of Microsoft products.

The announcement comes about a week after the European Commission approved the Skype-Microsoft deal, concluding that combining the two companies would not significantly affect competition.

"In the area of consumer communications, the investigation found that the parties' activities mainly overlap for video communications, where Microsoft is active through its Windows Live Messenger. However, the Commission considers that there are no competition concerns in this growing market where numerous players, including Google, are present," the EU said in a statement.

Microsoft announced plans to acquire Skype in May for $8.5 billion. It received approval in the U.S. from the Federal Trade Commission in June.

In recent months, Skype has added video calling to a number of Android phones and released an iPad app, but also battled a mid-summer outage.

Microsoft put together an infographic about the impact of Skype; click the image above for a more complete look.