A nice scoop from Geek.com's Russell Holly today, who confirmed what became was apparent after both the Galaxy S5 and the HTC One M8 booted up with "Powered by Android" displayed prominently on the splash screen. Those who like to pick nits have long pointed out whenever a manufacturer doesn't bother to mention their Android phone uses Android.
Holly notes and provides a doc from the Google Mobile services agreement that the logo's required at boot, and "should always be at the bottom of the screen horizontally centered." So get used to it.