I have acess to Media Create, NPD, and Chart-Track/GTK numbers at work and did some sums for the worldwide 360 sales and the most recent figues only come out to around 19.5 million. Actual numbers are probably a little higher for the various smaller countries that aren't tracked by the major companies.
I don't think 20.15 million is even possible for the 360 given the latest worldwide shipment figures from Microsoft's most recent quartely report, a reasonable estimate of how many 360s Microsoft has been shipping each month in 2008, and the number of 360s sitting on store shelves unsold worldwide.
For 20.15 million to be even possible Microsoft would have to made a dramatic increase in shipments relative to the previous six months of 2008 and/or less than Wii levels of stock sitting on the shelves worldwide.
There seems to be a fairly large number of mystery sales being reported for the 360 in the Others category along with a somewhat inflated North America life to date sales that come out to some 500-600 thousand extra 360 sales that have no data to back them up with.
