Back in the NES days people thought that the master system and Atari 7800 would eat up into NES's marketshare and cause the fall of it. Though that never happened but what did bring the NES down was when genesis was released. Though Master System was somewhat suscessful due to focusing on markets that the nes didn't do well. Like Europe
So useing the past I can say that in order for them to even outsell Vitalitly Sensor they will have to do somthing much better with killer software or focus on the wii's weakness and work there.
In concluesion Natal could focus on weaker markets of the wii. While the Move will improve the wii mote. Thing is. We don't know if the move is powerful enough to make the wii look dated or how natal could work with games. or the wii's weaknesses.
Time will tell.
For now vitality sensor. We all saw how Wii music sold without hardware or bundle. So for now my money is on vitality sensor








