hmmm...IGN certainly isn't getting excited for light gun peripherals. The beauty of the Wiimote is that it already functions like a light gun so the shell mostly just dictates how you hold your hands. Both Matt and Bozon think the Nintendo branded guns are crap and a waste of money.
They are excited about Medal of Honor, but that has to do with the controls, not the gun. And their jury is still out on Umbrella Chronicles.
I've never been too much into light gun games, but that's mostly because I couldn't justify buying a controller that I would use for a handful of games. With the Wii I may change my mind.