More importantly, the "K" build of Android is supposed to help relieve the fragmentation problem that has been a problem for Android since all the way back to Android 2.2. There are so many older models of Android floating around with just 512MB of RAM (compared to the 2GB on high-end models) that Google wants the new build to allow older Android phones to have some of the same features found on devices running Ice Cream Sandwich and Jelly Bean. This will allow Android developers to optimize their apps for fewer versions of the OS.
In addition, according to those with inside knowledge, Google is said to be developing low cost Android models apart from their mid to high end Motorola handsets. These phones are going to be aimed at developing countries to help Google tack on points to Android's market share and will compete with an oft-rumored low-cost version of the Apple iPhone that has been rumored for months.