Software sells hardware. So yes they will both sell systems. Thing is. How much? Can galaxy 2 appeal to those who didn't like the first game or will it sell to only those who bought the first one.
Will Metroid sell better than prime 3 or will it only appeal to those who bought Prime 3.
I think that it will push some systems. The 2 games will proberly stop the wii from slowing down too much. That's all I see right now