Definitely not too big at all, in my current experience. I just bought a 46" (ln46a650) and was freaking, thinking I'd bought too big. Nope. My viewing distance is about 8'-9'. After seeing it in the room, it's actually smallish. 52" and pushing it back to about 10" or so would have been Perfect.
I'm stiiting at a slight angle 12 feet away from where the screen would be and the wife 14 feet. Is a 52 incher too big? What would I not like about it to have to consider a 46a650?