I found the following link to Sony's documentation to find the width of the new 42" Grand Wega A10.
Alas, the same issue here as with the Samsung 42". They're both about 1" too wide. The 42" A10 is 39 3/8" wide, which means it's either a "really expensive" 37" panel TV or a heavy tube TV that will fit in the 38.5" wide cabinet (where 38" is truly ideal).
Maybe the 2006 models will have something that will truly work out for me. It's sad as these models are said to "fit in the same space as a 36 inch tube", when in reality, 36" tubes shouldn't take up 39+ inches of width.
It's very frustrating and unfortunate. I'm sure Sony and Samsung make a lot more off of their rear projection units than their tubes.