Acknowledging the impact of tablets, Intel's Otellini this week scaled down the PC sales forecast for the remainder of the year to 8 percent, down from a double-digit growth rate projected earlier this year.

"Even after I saw the numbers yesterday from Apple, and we get engaged in lots of Windows 8 and Android tablet design activity across the board, I believe this [tablet] category is additive to computing. I don't think it's going to replace any one category," Otellini said.

Many viewed netbooks as a different category, but they are value PCs with concessions on OS, screen size and performance, said Nathan Brookwood, principal analyst at Insight 64.

"Netbooks have never been a separate product category. They were a price point," Brookwood said, adding that tablets were complementary devices to PCs for lack of a keyboard and full productivity applications.

However, Daoud said that tablets nevertheless are having an impact on future PC and OS designs. Tablets thrive on media consumption and application delivery models championed by Apple, and Windows 8 might borrow some iPad features, Daoud said. As a hybrid OS combining PC and tablet capabilities such as touch, Windows 8 could redefine the way devices are built.