A few weeks ago the new Samsung Continuum was leaked - a Galaxy S variant but has two displays: a main 3.4" Super-AMOLED display and a secondary "ticker" display which is also an OLED (1.8", 96x480). This phone is now official, but it turns out that this is actually just one display (4") that is 'marketed' as two displays. The lower 'screen' is used for notification (Samsung calls this a 'ticker' display). Here's an official Samsung ad:

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