I just did a clean install of Lion on my 2010 MBP. It seems as though in the system preferences for the built-in trackpad, I have the option of setting the secondary click gesture to "Click or tap with two fingers", "Click in bottom right corner", or "Click in bottom left corner".
Previous to this fresh install, I had simply upgraded from Snow Leopard where I had been able to initiate a secondary click either by a two-finger tap or a click in the bottom right corner. That setting was preserved when I upgraded from Snow Leopard to Lion. When I simply did a fresh install of Lion, it's now either one or the other. Not both.
Does anyone know how I can get the "both" behavior back?