From the official Android Site:

Android KitKat
Prepare for a sweet new treat

Android is the operating system that powers over 1 billion smartphones and tablets. Since these devices make our lives so sweet, each Android version is named after a dessert: Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, Ice Cream Sandwich, and Jelly Bean. As everybody finds it difficult to stay away from chocolate we decided to name the next version of Android after one of our favorite chocolate treats, Kit Kat!

Android 4.4, KitKat
It's our goal with Android KitKat to make an amazing Android experience available for everybody
--jeremy