No, that's why they are making Super Mario Galaxy 2.

why drop an 8M selling franchise?

They'll keep both. proof is SMG2

Now if you said they'd drop punch out cause of low sales... I'd say it's possible... But why drop something profitable when you can outsource it and thus not harm your opportunity cost?

in the case of mario, the 3D and 2D may appeal to different audiences too, so having both is not necessarely counter productive, and the resources are probably better used amongst the 2 than by doing a sequel for a game that barely released... you'd eat it's sales.

This.

Also, while I'm sure NSMBW will sell amazingly, but it's not even out yet, so saying it's gonna sell 20 million+ copies as if it's a sure thing is kinda early imho.

Which is all based on the possibility that NSMB Wii will just sell 20 million like it's the easiest thing in the world.

Except if the company decides to make even more 20 million selling games, using the resources that were supposed to make the 8mill selling one. 

 If it succeeds, I can clearly see 2D Mario becoming the flagship franchise again, and we won't see more than one 3D Mario in a generation any more.

Because Nintendo is soooo big on direct sequels to their huge franchises? I can think of maybe 4 game series made by Nintendo that have had that happen this generation. 3D Mario will be safe because they will want to give 2D Mario plenty of time to sell.

You don't reach 20 million+ sales by releasing a sequel to a game relatively shortly after the original. 20m+ sellers like NSMB DS, Wii Fit, Wii Play and Nintendogs do so over the course of several years.

NSMBW wouldn't sell as much as it could if they'd release NSMBW 2 a year or so later. However, releasing NSMBW, and then releasing SMG2 the next year is fine. They're very different games, and won't cannibalize each other's sales.

Besides, everyone is talking about NSMBW as if it's a guaranteed fact it'll easily manage 20 million + sales. We'll just have to wait and see, who knows, it might never reach that.

Do the lower sales of the Mario sports titles stop them from making them? No, in fact I think there's to many of them. 3D Mario games are not doomed, and at the very least will keep coming at the usual rate of 1 per gen (possibly 2 if SMG2 sells well enough)

I dunno, you're comparing how super mario galaxy will look against an un-released 2D wii game based upon a successful (and longer in existence) DS game on a platform with a much higher install base.

19.5 million units of NSMB of 111.49m DS units is 17.49% (or there abouts)

SMG has hit 8.14 million from 53.97m wii's. 17.49% of the number of wii's out there is 9.44 million units. Now I don't mean to sound like a PS3 fanboy here, but let's not forget that NSMB had over a year head start on Super Mario Galaxy to get the percentage of copy owners it has. I'm not saying that SMG will sell 1.3 million in the next 12 months, but there's a possibility.

So I wouldn't count on SMG and SMG2 being the first sign of death for 3D Mario, far from it.

Also you have to consider that NSMB Wii is not selling on the DS platform, a platform that thrives on 5 to 10 minute play sessions, so therefore the appeal of NSMB Wii may not be as great on a home console. AND there's no guarantee that people who bought NSMB will buy the Wii game (I might not be, and I bought and loved NSMB) because there's been a few bad press moments with the game (slightly, but not adequately enough, up-res'd DS graphics comes to mind).

SO to summarise, I'm going to go with no, 3D mario is no where near doomed.

This is what I'm thinking about, good post!

I think NSMB Wii can sell 3-4m fast, but the rest of the sales is going to take a while to build up. And we don't know where it will end. 6m, 10m, 15m? But maybe not 20m.

Yeah, the demographic that wants 3D Mario might be smaller now, but it's very profitable. But next generation might shift and 2D Mario might sell allot less then a 3D would. Until that time, it might be good to feed the starving core gamers so they hang around. Same goes to casual games VS more core ones. The more people Nintendo can make happy and still make good money, the safer their future will be.