What I did with my plasma was move the equipment to its own rack off in the corner and put the center channel on a shelf below the screen.
You could also build a Flexy rack -
http://www.tnt-audio.com/clinica/flexye.html - to replace the one you have, and make it a little bit shorter. These things are brain-dead easy to make and look pretty good.
Of course, if the height of the screen doesn't bother you then there's no reason to go through the trouble is there