Code commit indicates the end may be near for Android Dalvik
In Android 4.4 KitKat, we got a bit of a preview of the next Android RunTime called ART (get it?) Google made it known that ART was planned to replace the current runtime, Dalvik; and, a new code commit to the Android Open Source Project makes it look like that switch could be coming very soon, as in the next version of Android.
The new code commit is pretty basic, but causes a big change: it switches the default runtime from Dalvik to ART. What that will mean in technical terms is that Android will switch from the Dalvik "just-in-time" compiler, where the app bytecode is compiled and run when you run the app, to the ART "ahead-of-time" compiler. This means that the app bytecode will be compiled when you install the app and only the pieces of the app you need will run, when you need it. In terms of what users will see, this means that apps will run faster and more efficiently, but they will also take up a bit more space on your device.
Of course, this is just a change in the default for Android. Dalvik isn't necessarily disappearing, but that seems to be the most likely end scenario here. We still don't know when the next version of Android will hit, or whether it will be a full version bump (5.0) or another incremental bump (4.5).