"Microsoft announced the Skype acquisition on May 10 and plans to connect it to Outlook e-mail, Xbox game console, Windows mobile phones and corporate-phone software."This is phase #1 of Microsoft's usual "embrace, extend, extinguish" strategy. Right now they embrace Skype and build it into some of their products.
The next step will be to enhance the Skype protocol with extra Outlook and Windows Phone options; these protocols will be proprietary, patented and certainly not published.
The final step will be to discontinue the Skype clients for OSX and Linux ('because their increasingly incompatibility with rich features the Windows platform offers Skype users'), update the protocol even further so that current Skype clients will stop functioning, and gradually remove the 'Skype' name and logo from their products, and eventually, from history.
The idea is to disadvantage any competitors, and to make Skype users switch to Windows or a Windows phone.