Xbox is an essential piece of the new Microsoft pie, says departing CEO Steve Ballmer

In his final speech as CEO at a Microsoft shareholder meeting, outgoing CEO Steve Ballmer fired a shot across the bow of those who are rumored to be thinking of splitting the company into component parts and selling some of them.

Like possible new CEO Steven Elop, for example.

One of the candidates for the soon-to-be-vacant CEO position, Elop is said to be considering just those kinds of possibilities — spinning off products like Xbox and Bing into their own companies. That is, of course, completely counter to the living room strategy Microsoft has been painstakingly building for perhaps a decade — with some degree of success.

“Microsoft is uniquely positioned to drive and define the next big thing,” Ballmer said, highlighting the fact that it is the very interoperability of its services that is the key strength.

Windows Phone, Surface, Windows 8, and Xbox all speak, of course, the same Microsoft design language, with boxes and tiles and angles and bright colors. More importantly, however, they work together, allowing Surface or Windows Phone devices to display content on TVs via the Xbox 360 or the new One, and sharing web favorites, preferences, and contact information.

There’s no doubt that Microsoft has invested billions into products with dubious return-on-investment potential — prime example: Bing — but there’s also little doubt that Xbox has been one of Microsoft’s few consumer device success stories.

Clearly, Ballmer wants it to stay that way.

Xbox could bring Microsoft something like $17 billion in a sale, potentially. But without the most popular gaming console platform in the market, Microsoft’s claim to gadget success, consumer adoption, and living-room domination would fade significantly.

And that would likely cost more than $17 billion.

Bing also helps Microsoft with other projects, including translation and natural language technology. However, its value is less clear, perhaps, than Xbox.