CoD 3 Remote

The gun of the NES??? no! but I think maybe of the another gun of duckhunt wii maybe
But, you have to remember that the VC games will have to be re-coded for the Wii. You for sure won't be able to use the Wii-mote on GCN games, because the code just isn't there on the disc to control it, but since there has to be at least some editing for the VC games, they may add in the abilty to use another controller, if appropriate. Not saying they will, but they could.
You'll definetly be able to use the Wii Remote gun attachment for Call of Duty 3. On the subject of the Wii Remote for vc games, I'm 99% sure that you will not use the accelerometer feature for any at all, but maybe just the buttons, but then again there arent enough buttons on the Wii Remote for N64 games. They may make you buy the classic controller (unless you have a Gamecube controller) to play any vc games.