This is Clear Sans - released in late 2013 by the Intel Open Source Technology Center Overal. It looks like a slightly more contemporary, humanist version of Arial. Overall, we can't see too much to get excited over. Do note that it comes with a very thin variant that Arial lacks.
PDF of the comparison is here: http://1drv.ms/1czPMjE
Glyph comparisons (Arial in blue, Clear Sans in red)
