Mmmm, Duck Hunt...good times even I couldn't shoot that dog.
Expect the Zapper to be used for a few games at launch and used as "secondary control schemes" in other games (if they do use it).
Peripherals never, ever sold well. It's a vicious cycle. People won't buy the peripheral if games don't support it. And developers won't support it unless there are people who use it.
On the plus side, the zapper is nothing more than a hunk of plastic. Developers could simply assume 2-handed game controls that don't use the accelerometers much. So a gamer could hold them in two hands normally, or put it in the Zapper mold for more comfort. It would be considered a perk in that case.
There is no such thing as a console war. This is the first step to game design.
