I don't find it that ugly. It is a bit overwrought, looks more like a concept car, so it will not age well. But it is certainly very interesting. We knew about the spindle grille for while, and overall it looks surprisingly similar to the LF-LC concept, which is quite striking.
The most interesting thing would be how this thing drives. The new GS is already known to be a better driver's car than the F10, so can the new IS be sportier than the F30?