It would depend on the size of your main speakers. If they are small enough to fit on the shelf, then just have one to right of the TV, at the edge, and have the left equal distance on the left.
If they are floorstanders, then I can see why you would have a problem, but with correction software on the AVR, you may be able to make it work.
Also with floorstanders, you could just have them positioned in front of the shelf.
As a side note, it has been my experience with furnished apt's that the furniture can be moved, as long as you don't damage them in the process.