Why wouldn't Microsoft want to release "Xbox 720" one year before the PS4?

[epicberserk]

What I think is their two options 1if natal fails to deliver the heat and hype to increase marketshare and flops microsoft next weapon will be a new third xbox to be first or option2 they will sell the 360 at low price and Have a high end price for 720 similar to ps2/ps3 senerial