I feel Nintendo will win the portable wars. Why? First off, current owners of ANY game boy system can upgrade to this and still play their games. Nintendo has over a decade of working with portable units. They have learned some things. They have pretty much two products at the moment, Gamecube/games GBA/games. That is all they do. They are not a division of a larger company, so personally I think they would be more likely to last longer if an unfavorable market came along.
(Did you also know Nintendo is over 100+ years old?
Started out making playing cards.)
Not being flamebait or anything, just something I've thought about.