Although in beta at present, a finished version of the software needed to make all of this work is due to be released in the coming months, the two companies said in a joint press release.
"This first-of-its-kind interoperability between consumer IM leaders Microsoft and Yahoo gives our customers tremendous control, convenience and freedom in their web communication experiences with Windows Live," said Blake Irving, corporate vice president for the Windows Live Platform at Microsoft.
"We are proud to deliver this latest advancement in IM services that empower people to communicate with virtually whomever they want, wherever they want and whenever they want."
It is possible that the shared IM community this could create might hit 350 million users. I am personally looking forward to a time where I will be able to use IM or VoIP with anyone, regardless of the software used, as we currently can with email.