Sony does note that availability of the 4.0 upgrade will vary by market and, not surprisingly, carrier requirements.

ENGADGET: Sony starts delivering Ice Cream Sandwich update to Xperia go, Xperia U and Xperia sola

But the landscape of the living room is changing, and Sony and Microsoft need to take note to avoid being left behind.

FORBES: Valve's 'Steam' Enters the Living Room. Do Sony and Microsoft Need to Worry?