9to5Mac has found references to new iPad models in iOS 7.1. Specifically, they have found iPad models named iPad 4,3 and iPad 4,6, where 4,1 and 4,2 are versions of the iPad air and 4,4 and 4,5 are versions of the iPad Mini with Retina Display. 9to5Mac speculates that these could be simple hardware tweaks, potentially to optimize for cellular networks in China.
When I first read this, I was hoping for an iPad Air and iPad Mini with Touch ID, but I don't think that's it. I know many people were hoping for Touch ID in the iPad after the iPhone 5S launched but many reports have said that the Touch ID sensor was the component that was slowing production of the iPhone 5S. Maybe the next iPads will have Touch ID.