I agree with John.
From the Axiom FAQ:
"Where should I place my surround speakers?
Ideally, surround speakers should be either wall-mounted or stand-mounted to either side of the couch or primary listening area, from one to six feet higher than seated listeners' ears, and slightly forward or rearwards of the listening area if you wish. Axiom's Quadpolar surrounds are especially versatile and can yield excellent performance with stand or wall-mounting to the rear as well as at side locations. (see our dedicated stands for the QS Surround speakers in the Store). Rear center speakers for 6.1 and 7.1 installations are intended to go on the rear wall at about the same height as the surround speakers."
You don't say how far in front of the pillar the couch will be placed, but even if the back edge of the couch was even with the front edge of the pillar, you should be able to get the surrounds on the side walls just slightly behind the heads of the listeners and still have a direct line of sight from the couch to the surrounds. If the couch will be even more forward than the pillar, you should have no problems at all.
If push comes to shove, and you find you have to place the couch where indicated in the drawing, though I prefer slightly behind, you could place the surrounds on the side walls slightly in front of the couch.
