Just done the same thing myself. Should be fine - BUT...
I went from a 46" Toshiba LCD to a 46" Panasonic Plasma and found the mounting points on the TV were the same position and the same thread size as the fittings i had before.
Its not so much the bracket you have to worry about (although some TV mounts are size-range specific), its the fixtures and fittings, and making sure you still have the other screws etc from when you bought the TV bracket!