I will go to the best one scenario in term of selling power :
- 150$ arcade + natal + natal game
- 250$ elite + natal + natal game
I m not sure they will release "cheaper" sku without Natal to push at the maximum they peripheral (you buy 360 = you buy natal)
I also doubt they will release a Natal console wo a Natal game inside
I also expect Ninty to cut their price, but, I m less sur about this one since Ninty do not like to react to competition and follow their own calendar (and still sell like hot cake)
For the PS3, I expect a 250$ entry price at best but I m not sure about the motion control/game
EDIT : they may lose money in the operation but they have money
Time to Work !