DxO lab just published the Sensor test result of Nikon D5100 camera, The overall numerical score of Nikon D5100 was 80 , Sony’s acclaimed 16 Mpix sensor already used on the Nikon D7000 was rumored to be used on this camera.
see more at DxO lab
Nikon D5100 vs D7000 vs Nikon Pentax K-5