Would there be a sound problem if I mounted my FRONT L & R 522D bookshelf speakers in the FRONT left and right corner of my living room?  (about 7-8 foot high)

Very similar to this picture except in the front (from Ron Binshtok's theatre).

Sorry for that big azz picture

If your going to mount them that high, you just have to be aware that your going to be in the reverberant field at all times.  What does this mean?  Your not going to have a definate stereo image, bad for home theater and critical music listening.  If your looking for just background type music listening, I don't see a problem with it, actually, they might sound better 'up there' if your just looking for background music reproduction.

Now, if you can tilt them down to point at your seating area, you might be ok if you don't mind that your imaging to your video display is going to be way out wack...

Depending on your room size and the location of your center channel speaker, you may also find that the sound field dips when HT sound moves from one side of the room to the other. We originally wired our 15x15 great room for high-mounted L-R speakers. However, after visiting a friend's house that was set up this way, we decided to place them at the traditional height.

-Ken

PS: We also decided on tower speakers, which would not have looked good up high.

I wanted to mount two 422s much like in the picture above for my rear channels...is this also not an optimal solution?  (I could put them on stand in the rear)

If I do mount them on a back wall should the be tilted down or something of that nature?

Thanks,

Steve