When is the new xbox 720 going to release?

2015. their will be a new Xbox 360 this year(2010) but it wil be slim and redesigned. the new xbox will be released 2015 because Microsoft said the xbox 360 will have a life span of atleast 10 years. the xbox 360 was released in 2005. so 2015 at the earliest. and it probably wont be called xbox 720