"We've been working on this product for a while, and I just didn't want to miss today," Jobs told an audience that included bloggers and Apple enthusiasts. "Thank you for having me."
He did not address his health or say if and when he would return.
Tablet computers existed long before the iPad, but it took Apple to build a device that made sense to consumers. Apple simplified the software, designed a sleek, shiny shell and sold 15 million of the iPads in nine months.
The iPad was initially used for checking e-mail, surfing the Web and watching online video. But as the number of apps grew, the tablet made itself at home in offices, shops, restaurants and countless other settings.
Competitors including Dell Inc. and Samsung Electronics Co. have been trying since last year to lure consumers with smaller tablets, without much success. In February, Motorola Mobility Inc.'s Xoom went on sale with a new version of Google Inc.'s Android software that was designed for tablets, not smart phones.
For a moment, the Xoom looks promising, with a comparably sized screen, a faster processor and a few other bells and whistles the original iPad didn't have. But the iPad 2 catches up again with dual cameras and a faster chip inside. It pulls ahead with a slimmer profile and the ever-expanding number of tablet-specific apps.
After its March 11 U.S. launch, the iPad 2 goes on sale March 25 in 26 other markets, including Mexico, New Zealand, Spain and other European countries.
Apple also introduced updates to the software that runs on the iPad, iPhone and iPod Touch. The company said the update, iOS 4.3, will work on iPhone 3GS and iPhone 4 models, except the new version for Verizon Wireless.
Among other things, the new system turns iPhones and iPads with 3G cellular connections into personal Wi-Fi hotspots, so you can share the connection with computers or other devices — if your wireless carrier allows it. Many charge additional fees for this service.
Apple also announced new software designed for the iPad, including a $4.99 version of iMovie for video editing and a $4.99 version of GarageBand, its music recording and editing software. GarageBand includes instruments that can be played by touching the iPad 2's screen, and it can even sense whether you're tapping quietly or banging on the "keys."
The company also said Random House became the last major publisher to agree to sell its titles in Apple's e-books store.
Shares of Apple, which is based in Cupertino, Calif., rose $2.81, or less than 1 percent, to close Wednesday at $352.12.