Dragon007,
I think that if you posted how you thought the Nintendo DS would sell over the next 4 years people would understand your prediction better; in particular if you give reasons why the DS performed as you predict. Here is mine:
2008: ~30 Million systems sold, total sold ~100 Million
2009: ~25 Million systems sold, total sold ~125 Million
2010: ~20 Million systems sold, total sold ~145 Million
2011: ~10 Million systems sold, total sold ~155 Million
2012: ~5 Million systems sold, total sold ~160 Million
2013: ~5 Million systems sold, total sold ~160 Million
In my opinion, after the Nintendo DS hits 100 Million units sold it will become much more difficult to expand its market at the same rate it has been; the reason for this is that many of the people it will have to sell a system to will have never owned a handheld system before. At the end of 2010 Nintendo will release a new handheld system which will effectively put the Nintendo DS on its final legs and sales will be reduced to replacement systems, and as an inexpensive system to buy for your 6 year old child.