I think PS3 will have a great success both in NA and in the rest of the world when it will get cheaper. Blu-Ray can help, but right now very mildly (nothing to despise, though, every help is welcome), perhaps more in the future.
Well, as far as I am concerned, even Wii is still too expensive, but it's almost sure that it will be the first to become cheap enough for the vast majority of potential buyers and I think that it will be the first and perhaps the only one of this generation consoles I'll buy.