If I follow your logic correctly, someone who bought a PS2 to play sports games and bought a GT or GTA game, is a core gamer. But someone who bought a Wii for Wii Sports and bought Zelda or Super Mario is still a casual gamer. """
==>yes, it is something like this
the problem is not about core gamer or casual
the problem is about WHO buy a console during the first year ?
who is driving the sales of the Wii ?
PSX/PS2/Xbox/Xbox360/PS3/GC/N64 (u can add every console)
==> hardcore gamer
and do you know WHY ?
because the main target of the Wii is the casual market : Wiisport/Wiifit
During the first year of the PSX/PS2, the userbase was 100% hardcore.
And later it was diluted by core and casual gamer.
The game that made the success of the PSX/PS2
==> hardcore game
The game that are making the success of the Wii
==> casual game
Wii is not a PS2, it is a Wii
Even if it sell 1 000 000 000 WW, it will not be a PS2.
Of course, if the third party developper begin to make good game on Wii or begin to adapt Streetfighter/GTA/CoD (etc...) to the Wii
it will be the ultimate console as the PS2 was.
If this not happen, then people will buy another console to "complete" the Wii
the PS3 or the Xbox360
How do you know that the Wii sales are driven by casuals? Which numbers do you have to support your claim? It can't be attach rate. If it were, the PS3 would be driven by casuals too, because the attach rate is comparable. So how do you know that the Wii sales are driven by casuals?
Most 3rd parties won't have any other choice other than to adapt to the Wii if they want to survive in this industry. Some of the traditional franchises that didn't start development in 2005 or 2006 have already been moved exclusively to the Wii (Monster Hunter, Fatal Frame). Konami, at first they didn't plan to make a Wii version of PES, now they are doing one and are trying to make it right with a new passing system among some other things.
3rd party support for the Wii is clearly improving, not only in quantity, but also in quality. As more good games are released for the Wii, 3rd parties will see better sales of their games.