Interesting - but to quote from the Android developer website: Typical good candidates for the NDK are self-contained, CPU-intensive operations that don't allocate much memory, such as signal processing, physics simulation, and so on. When examining whether or not you should develop in native code, think about your requirements and see if the Android framework APIs provide the functionality that you need.
What is like working with the NDK? C++ is the one language that can work on both iOS and Android (and Windows phone?) Personally, I'd like to get some reuse out of my iOS code. I'd do more C++ if I knew that I could reuse it. Of course, Objective C could actually be portable too.
C# can do that too, using Xamarin.