The iPad mini is rumored to sport a 7.85-inch screen and a price of at least $299. But when and if it debuts, it will not enter a vacuous 7-inch tablet market. Its opponents will compete on price, ecosystem, performance, and features. Each offers something unique, and Apple's new tablet will have to be an amazing piece of kit to answer the challenge. ©2014 CBS Interactive Inc., a CBS Company. All rights reserved. Used by permission.