Ballmer spent time saying he appreciated efforts of various Windows 8 tablet makers with past PCs and coming tablets, but added: "With Windows 8, we didn't want to leave any seam uncovered...Much like the need for mouse [introduced with Windows 1.0], we wanted to give Windows 8 its own companion."

Analysts were concerned that Microsoft might rankle its tablet makers. But the news surprised some analysts, including Steven Osinski, a member of the board of the business administration college at San Diego State University.

"It seems to me that Microsoft, the sleeping giant, has finally woke up to 2012," he said. "If Surfaces works as well as Microsoft claims, here's a product that will give Apple's iPad a major run for its money."

Features in the tablets include a built-in stand, a vent around the perimeter to let off heat and partnerships with Netflix, and inclusion in the Xbox network, he noted. "This will be a threat to Apple's dominance in the tablet market," Osinski added.

The face that Apple has a two year start on Microsoft with its 9.7-in iPad that starts at $499 will matter. The iPad currently has more than 60% of the market, while various Android makers split the rest.