The only way I can see true Arcade Lightgun games being what they originally should be instead of this dumbed down Wii on-screen cursor limitation is if some peripheral maker decides to produce gun hardware with seperate bar sensor and works perfectly with CRT and LCD's TV screens alike. Maybe it could be plugged into the USB ports which will also finally see the Wii getting use out of it. But even so and most importantly, the game developers will have to take time to implement support for this hardware like the issue of compatibilities and the many different types of TV screens out there.
It would be quite costly for the technology, hence the reason why I don't see true Arcade 1:1 Lightguns games on the Wii which is really a damn shame. Only choice is the go down the Video Arcades themselves if you love pumping in £1 coins for the true experience, or back to the games on the older consoles with your ancient but reliable CRT TV.
Anyways I am looking forward to Metroid: Other M myself. Hopefully it will work will on the Wii as it needs a decent Devil May Cry/Ninja Gaiden style of game. Maybe it will open more doors for Tecmo for more games on the system.
EDIT - Totally forgotten about Monster Hunter Tri. It's already been out in Japan, so it will take a while to reach our shores. And then there is also Muramasa: The Demon Blade.