According to Matt from IGN
http://blogs.ign.com/Matt-IGN/2007/10/23/69722/ And from the sounds of his blog the improvement is significant!!
Wow i haven' t even got my hands on Metroid Prime 3 yet, and there is already improved FPS controls on the Way!! He (Matt from IGN) did say Metroid Prime 3' s controls were ace and most reviews tended to agree with his intial assessment, so these comments regarding the latest MOH for Wii is welcome news indeed. Great job EA, great job!! With 32 player online and potentially better controls then Metroid Prime 3 looks like a possible purchase for me.