Nokia will be announcing a new phone tomorrow and the Conversations blog posted a teaser (http://www.gsmarena.com/nokia_to_announce_new_asha_phones_tomorrow_in_new_delhi-news-5992.php) that shows nothing but a single rounded button. Popular leak source @evleaks may have just allowed us to take a better look at tomorrow's new device (as always, take it with a pinch of salt).
It's called Nokia Asha 501 and it is a full-touch device. Interestingly, there's only one physical button under the screen (presumably the one from the teaser image), while current touch Ashas have two