Another mystery phone destined for Sprint? (Or just random presentation fodder?)

Jerry Hildenbrand 16

Like our tipster, at first glance we were sure this was a stretched out LG Optimus S when it showed up in some Sprint training materials with no explanation or even a hint attached.  But after a closer look at the buttons, and the area where the screen ends towards the bottom, we're pretty sure it isn't. We know that LG has something in the works for Mobile World Congress, but the leaks...