Dell teased its Intel Bay Trail-powered 8-inch Venue Pro tablet at the Intel Developer Forum last month. On Wednesday, the company introduced several 11-inch versions of the Venue Pro.But don't think Dell is buying into the notion of a post-PC marketplace: It also introduced three new Ultrabooks bearing its XPS brand, including an 11.6-inch, 2-in-1 convertible, and a 15.6-inch model tricked out with discrete graphics and an eye-popping display with a resolution of 3,200 by 1,800 pixels.