Wow, there's a lot of misinformation about Metroid Prime: Trilogy being thrown around in the thread. Obviously, the Wii is more powerful than the GameCube.
Metroid Prime (the original) featured smoke emitting from the arm cannon when firing a lot of power beam shots in a row. In addition, other effects, such as the arm cannon freezing over when charging the ice beam, and burning when charging the plasma beam were present. These features were removed in Trilogy because in the GameCube game, these are simply 2D images layered onto the screen, which was fine since the arm cannon always appeared in the same spot on the screen. Obviously, that wouldn't work with the arm cannon moving around on the Wii. For Prime 2 and 3, the effects on the arm cannon were finally modeled as full particle effects on the cannon itself, so moving the Wii Remote around works just fine. They didn't fix it for Prime 1, because let's be honest, why do the effort?
And for this widescreen cropping during gameplay - I don't know where that's coming from. The gameplay is very much 16:9. However, the cutscenes are cropped: since the original cutscenes were in 4:3, the new cutscenes had three options - zooming in slightly while keeping it 16:9, putting black bars on the sides of cutscenes, or remaking every single cutscene. They chose the first option.