The biggest product debut of the week was Wednesday by Apple CEO Steve Jobs, putting in an appearance on stage in San Francisco even though he's on an indefinite medical leave of absence (he was diagnosed with pancreatic cancer in 2004 and has taken time off due to health reasons several times since then).

The new version of the iPad, generally credited with igniting the current fervor for tablet-style devices, sports a new design and features including built-in cameras and a new gyroscope. Though it was generally well-received, some critics were lukewarm.

"The announcement was as expected," said analyst Jack Gold of J. Gold Associates. "I don't see any overwhelmingly compelling capabilities that would make people sitting on the tablet fence go out and have to buy one, despite some attractive apps."

Such quibbles may be beside the point, however. The iPad is leading a trend in Internet-connected mobile devices that is siphoning professional and consumer demand from desktop, mobile and netbook computers -- in short, away from the entire PC category.

For its first fiscal quarter, Apple sold 7.3 million iPads. Along with iPhone and Mac sales, the iPad helped the company reach . Recognizing the key role the iPad plays in mobile computing, investors pushed up Apple shares by $7.44 Thursday to $359.56.