Yes and No.
The height of the TV opening is 35". A 46" LCD is roughly 31" and a 52" is roughly 33-34". Either would fit but not if I had a riser. If I did have a riser I wouldn't need the hutch to hold the center speaker.
The problem with the riser on top of the base unit for the TV to sit on is that it would have to be rather high to accommodate a large center. I haven't yet decided on which speaker but looking at the SVS MTS-01 that is 10" high and 12" deep.
The current base is 25.75" high. I can make another one that is slightly lower (maybe 23.25") by reducing the size of the component area. But even then, 23.25 + 12 = 35.25. Add the fact that the center of a 52" LCD is roughly 20" + the height of the stand, the center of the TV would be 55" or more off the floor and that just seems way too high to me.
I think my only real option is to take a loss and build an entire new unit with a hutch that is wide enough for a larger TV and deal with the sound issues by angling the center down towards the listening position.
This sucks.