Google doesn't seem to have any particularly good plan (at least not in public) for dealing with the Java anchor, even after the Oracle lawsuit, which I find very concerning as an Android developer -- like, when, if ever, are they going to support Java 1.7 or Java 1.8 features? Seems like they are content to be stuck at Java 1.6 forever. So not only are you practically stuck with Java if writing non-game "native" Android apps, but you're stuck with an old and increasingly obsolete Java.
The fact that I can't read past the weasel wording here though suggests to me that when Canonical says "native" they mean "QML running on top of Qt", which isn't really native at all (if I can't hook into it at the C/C++ level). I'd love to be wrong though.