Nice lens. I'd like to see all of it sharp, especially since the bright white background seems to bleed into the lens where it's unsharp. Smaller stop, more DOF, would cure this.
I think that the shallow depth of field could have been used better here. If you were trying to draw attention to the L you should've made it red to stand out. Try a different composition, the subject is too centered for my taste.
i pers think if u were gonna use shallow dof here, that you should have had the focus on the 17-40 - which is the name of this lens. the 'L' is too small and most people won't get the significance, imho