Courtesy of Engadget, we know the official name is now Sony Tablet P. It'll sport a Tegra 2 chip, 4 GB with a 2 GB memory card, and weigh in at 190 grams versus the iPad 2 at 601 grams, the Sony Tablet S at 600 grams, and the Xoom at 730 grams.
A couple of things about this.