Nice one, like redgar said, smexy :P
Anyways, I believe you should do 2 motion blurs in 2 different directions so you don't leave the top of the head and generally it should fill the rest of the empty parts that should be filled with a semi-vertical motion blur.
Also you should put the motion blur in another layer and delete the motion blur that is under the feet because that will give the gfx the fill that the render is SITTING somewhere and it's not just floating in mid-air.
Also, The text shouldn't be in the corner, but somewhere in the dark area on the height level of the head of the render.