As Android is mostly targeted at ARM, you could possibly target
your spare time and good intentions to ARM as well.
1) Compile your code statically with whatever compiler you wish
(e.g. GCC). Should work as long you don't interfere with
Dalvik-controlled UI. Statically compiled C code works fine,
there is no reason D should not.
2) Compile your code against 'bionic' - Android's analogue of
glibc.
This would be a very (to say the least) demanding task.
3) After completing 1 and 2, you could possibly start to look at
NDK - Android's native development kit, that has a well-defined
API with the Java.
I would not seriously consider coding in D instead of Java.
Neither D, Java nor Android are close to that.
Check out 'trimslice' as a possible development platform for ARM.
