JNI is supported by the Dalvik VM, this is how nearly all the native libraries are called from Java.
However, at this point, native code is not officially supported in application packages, even though
there are tricky ways to achieve this.
On the other hand, we're currently preparing a Native Development Kit (NDK) which will provide
tools for application developers who want to add native code to their apps, as well as officially
sanctioned APIs (i.e. header files) that will be guaranteed to be supported across all future
platform revisions, including the JNI-related headers.
There is no ETA on this yet, but it will be available as soon as possible.