As your article said it's going to happen , 360 has done fair enough to hold on that long . It even suprised me that it's going to pass 50M , I didn't predict this because of all the famous 3 lights of doom problom that was with the console on it's early days & though it was fixed but still the second (Falcon) also had it's probloms even though it was way less than before .
I admit the guys at Microsoft gave Sony a lot of hard work this time around , that also means a big user base for 3rd party on XBOX machines for future (8th generation) .
I would say if Microsoft keeps repeating what it's done so far then 4M gap will be covered in a year & a half, maybe on March 2012 or maybe till June 2012
And yes I think Kinect will slow the catching (It's not like WII console , Control & console sold together) but it will help raise sales of the console especially in USA
