My experience putting the De Capos close to the back wall differs from Andy's.
Although I agree that my speakers do sound much better pulled out a ways into the room, due to my wife's aesthetic realities, the De Capos are usually pushed back almost as far as they can go. In fact, my set up doesn't differ significantly from yours: the speakers are back almost against the wall with a 29" Sony TV between them. The left speaker is pretty much in the corner, although the TV is far enough away so that it's not really confining the speaker. The right speaker is just inside the doorway leading out into our foyer. In spite of this far-from-ideal setup, the speakers still sound wonderful in the room.
If you have the opportunity to try them out (I think In Living Stereo in Manhattan is a De Capo dealer and may let you audition them or at least offer some kind of return or exchange policy), you should do so before deciding that they won't work. Good luck.
Jon