Natal on 360 is mostly a teaser and preparation for it being embedded in the next generation. 35-40 million console owners aren't going to buy into Natal so there will only be a handful of games that are Natal compulsory, a number of games that are Natal optional, and many games that don't use Natal at all. Natal is unlikely to significantly drive 360 sales forward, especially not for 4 years.
As for the OP. No chance the 720 releases in 2010. There is a chance they will announce the 720 at one of the 2010 conferences, but not the unit itself.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
