AllThingsD has recently revealed that the iPad 3 will be launched in the first week of March.
This seems to fit with the recent rumors that Apple’s next iOS 5.1 will be released the beginning of March, after the company published carrier’s profiles in Japan, France, Greece, Finland, and Sweden indicate a March 9 release date for iOS 5.1

This is an excerpt from AllThingsD:

Sources say the company has chosen the first week in March to debut the successor to the iPad 2, and will do so at one of its trademark special events. The event will be held in San Francisco, presumably at the Yerba Buena Center for the Arts, Apple’s preferred location for big announcements like these. No word yet on a street date for the iPad 3 (assuming that’s what it’s called), though my guess is retail availability will follow roughly the same schedule as that of the iPad 2: Available for purchase a week or so after the event.

Meanwhile Apple.pro got hold of a back rear shell purportedly belonging to an iPad 3. According to these images and to the people who inspected the cover, the iPad 3 will have a bigger battery (needed with an HD display), a redesigned logic board and the camera will be moved closer to the edge of the device.

Under the hood it should feature the A6 quad-core chip, increased RAM and possibly Siri.