I know you would have to change your past analysis if you changed the software numbers but I don't see a way around .
My estimations for software number would be something like :
80% third parties at 12$ revenue, 10$ margin.
20% first party at 35$ revenue, 30$ margin ( console makers do make a killing on first party, they earn what a third party would earn + the licencing fee, MSFT made a fortune on Halo 3 last year, it will be tough to beat that this year)
This averages at 16.5$ revenue, 14$ margin for software.
PS : I think the real explaination for Q4 2008 loosing money is that it was the first quarter with Euro price cuts reduction and MSFT sold a lot more consoles in Euros than elsewhere that quarter and that price cut was huge ( 150$ time 1 million console sold in Others that quarter = 150 million$).