Coming with a 2.0 update.
The iOS monopoly on Toad Rally appears to be ending next week.
Nintendo's Japanese-language Twitter account has announced that Super Mario Run will launch on Android next Thursday (March 23) in the Japanese Google Play store.
Signups for notification are available in local Google Play stores now. The full unlock for the game will cost $9.99 US or equivalent, as is currently the case on iOS.
UPDATE: Nintendo of America has confirmed the Thursday date as well, and the game will update to 2.0.0 at that point for both platforms.