At its Gamasutra-attended CES press conference in Las Vegas on Monday, Sony made clear where its future lies: in the network.

Sony execs, including CEO Sir Howard Stringer and consumer products head and former PlayStation boss Kaz Hirai, explained how the Sony Entertainment Network will serve as the backbone of Sony’s wide array of consumer entertainment devices, from TVs to PlayStation hardware to new tablets and smartphones.

It’s all indicative of Sony’s initiative to take its relatively loosely-related products and use the “cloud” to more tightly integrate entertainment, by allowing consumers to use one common ID across all platforms, and one digital wallet. And PlayStation will play a key role.

“We have a stake in every part of the entertainment revolution,” said Stringer, and that’s what makes product unification via network important for the firm, which has sold 900 million devices worldwide.

Sony’s new line of tablets and smartphones are leading the company’s expansion plans, and the company is adding new PlayStation Certified products, including the newly-announced Xperia S Android smartphone, to its lineup.

The firm also unveiled the Walkman Z, a wi-fi enabled, Android-based portable music player with a touch screen and access to Android’s app marketplace. The Walkman Z will be able to play games not only on the built-in screen, but it also is the first Walkman product that has an HDMI output, allowing players to view games on a large screen.

(A demo of the Walkman Z displayed Vector Unit’s jet skiing game Riptide GP, which looked relatively sharp despite being blown up on a larger screen.) Walkman Z also has wireless connectivity to DLNA-enabled TVs.

Even as Sony expands its line of mobile devices that are PlayStation Certified, it’s PlayStation products like the PS3, PSP and new Vita that continue to target gamers more directly. As with other Sony products, the company is expanding the functionality of PlayStation hardware, adding network and social functionality to the PS3 and introducing those features on the Vita, which launched in Japan late last year and is due for U.S. release February 22 ($250 for a wi-fi version, $300 for 3G plus data fees).

Hirai said that as of January 5, the Vita had sold 500,000 units to consumers since its Japanese launch. PlayStation hardware sold over 6.5 million units during the holiday period worldwide, he added.

Hirai also revealed that Sony’s cloud-based, cross-platform service Music Unlimited will be available at Vita’s launch in the U.S. and UK, and that Netflix is aiming to have its video streaming app ready at launch as well.

Creating an integrated experience across all of Sony’s products is an initiative that in some ways was born out of the PlayStation business, which has the underlying PlayStation Network infrastructure and services. Taking that network expertise from the games business, applying it across the board at Sony, and successfully leveraging its massive product line could make the firm as formidable as it ever was.

“Whether you’re playing games, watching movies or TV, or sharing photos or videos, you’re really doing one thing – experiencing the content you want to,” said Hirai.