I'm not fond of the Wii for shooter games. The Wiimote isn't the most ideal setup for it in any shell and IR guns are sorta iffy. At least the Guncon3 for PS3 is designed specificly for rail shooters and such.
But I am a light gun fan, so I have a Guncon1, two Guncon2s, and two third party guns capable of Justifier/Guncon1/Guncon2 modes.
Not to mention, House Of The Dead 4 might be proted to the Wii and that's a shame. HOD4 runs on a Sega Lindberg rig, which has as LOT more power than the puny Wii. So the port would have to scaled down for the Wii if it happens.