TV and/ or system rack between speakers...

I have a large tv that will have sit between the speakers. To what extent will this configuration screw up the sound stage?

Unless you can try it with & w/o the TV in the middle, it`s an impossible question to answer as no one will have the exact gear in the exact position in the exact room. Since the TV must live there, why agonize over it? Since we don`t live in a perfect world (a revelation to many audiophiles), kick back, & enjoy your system.
I have the same issue but witha smaller screen. I really don't think that is has "screwed up"it has altered it to it's own sound. My speakers, Revel F32's, in this configuration do a very good job of imaging and staging. The sound is off the floor and has a very good presentation.
I really don't think the TV, 34"glass screen, has hindered
at all. I once tried placing the echo busters in front of the TV and the stage seemed to fade and dropback.
Perhaps yours is a combo 2-channel/HT system and you don't want the screen to affect the image when you're listening to stereo. In that case see if you can place the speakers a bit ahead of the screen. Then put a padded room divider, or a Japanese paper screen, or an acoustic absorber or diffuser, or, hey, a bushy plant why not, in front of the TV screen when you're listening to music. (Or do what I do, place a padded quilt over the TV.)

I have had to share the listening room with the TV since last year. The TV is small enough to be placed on a movable stand. I slide it well back and cover it with a quilt when I'm listening to music. If I don't, the image is flattened like a pressed flower.
Thanks guys, I should have my speakers in about 3 wks. If a quilt over the tv still screws up the soundstage depth, I`ll concider a corner placement.
As Tobias suggests, mine is a combo 2-Channel/HT system. My current configuration is a Sony 36 XBR flanked by a pair of KEF 104/2s at 92" oc in a 14' wide room. Horizontal and vertical imaging seem excellent, but I sense a lack of depth. The face of the monitor is 3" behind the plane of the speakers, but there is room to move the monitor back a foot, for a total of 15". Would doing that and covering the TV help stereo depth? Of course that exacerbates an already small video image; the TV is heavy to move back and forth on carpet even with casters.

A related issue is that I've been trying to decide between the more practical -- room darkening and bulb life -- 60" Sony SXRD rear projector or a 100" Stewart FireHawk screen with either a Sony HS-51a or 100 (so called Ruby) front projector. FP eliminates the mass between the speakers; RP is less deep than my 36 XBR but wider. Is it the width or depth of the interposed TV that reduces perceived depth of soundsatge? That is, would a 60" plasma screen when they become available be just as harmful to depth imaging?

Any advice would be appreciated.

Donbellphd, moving the TV back 15 inches and covering it with something thick or padded will probably help you get some depth back. You'd have to try it to see how much--and also to see how much of the screen you could still see !

Your second question is an interesting one. For me the critical point is the position of my (quite deep but not too wide) 16:9 CRT TV with respect to the front plane of the speakers. I have not tried substituting a shallower TV unit to see if it makes any difference, though.

In its forward position my TV is about 4 inches back from the speakers' front baffles. Backed off, this distance is about thirty inches.
In my experience, a tall vertical rack and/or big TV between --or just behind-- the plane of the speakers is the fourth cause of getting mediocre sound from high-end speakers (poor imaging). The third cause is speakers placed too close to the front wall/sidewalls (boom, no depth, spurious images). The second cause is speakers placed non-symmetrically in relation to rear wall and sidewalls (wrong soundstage, deformed images). The first cause --in order of importance-- is a squarish room or otherwise bad room (reinforced room modes with nasty, non-equalizable nulls). I understand WAF and all that, but I think of the wasted money when I see so many pictures of wonderful systems with all of the above. Sorry for the rant.
Vladimir, that was very helpful. Thanks. Because of your post, I`ve decided to place the speakers along the long wall and find a new location for the tv. Hell, I might sell the damn thing and just keep the one tv in the bedroom.
You're welcome.