I'd go from Nintendo to Sony and vice versa.

If Nintendo went out, I'd probably stop console gaming, as the PS3 and 360 aren't providing enough of the games I enjoy. :(

I remember that Nintendo said that if they went down, their franchise IP's would be taken with them so nobody else could use them.

 Actually they are different in many ways.

If Nintendo would stop making Hardware, I would go to whereever they produce the Software now.

I would leave the gaming market altogether if Nintendo died. I have moral objections to Sony and philosophical objections to Microsoft so PC, 360 and PS3 would be out.

If one of the three left I think a new console maker would appear. Apple? IBM? NEC (Turbografx-16) again? Even AMD? They all have either resources or branding that would help in that field.

Nintendo won't die though, look at their profits during N64 and GC eras.

I would fall through the skies at a dangerous pace,
Ne'er would i find a more perilous place,
Nintendo would rend away my sooooouuuulllll....

Id sing lamenting nonsensical songs for a long time if Nintendo were to quit.
Probably would quit gaming and take up MMORPG's on PC :(

yea i'd go PC only if Nintendo left.. blizzard is still my 2nd favorite developer.

But nah.. We'll leave the luck to the heavens ;)

I would probably end up being a normal, mainstream console-gamer, slowly watching the console industry become part of the pc-industry. I would still play 360 and PS3 (I'm buying a 360 in december, no matter what happens), but without the man with the mustache, the boy with the green hat and the woman with the round shoulders, life(gaming) is just like 80-90% pointless...
After that, I would become a retro gamer only talking about how great gaming used to be.

scenario 2: I would dedicate my life to the resurrecting of Nintendo and I will become either the Fourth President of Nintendo and become a multi-millionair, or a paranoid lunatic somewhere in a mental hospital ;)

It's either one of those or Nintendo just keeps on being alife, kicking and making profit :P

If nintendo were to die which is unlikely then Id go to which ever console had mario and zelda on.

If playstation then to xbox and vise versa.

If sony or microsoft were to stop making consoles than I dont think that many people would care as they're are very similar. But if nintendo dies it would be a sad day in gamaing indeed.

 Actually I think that most of Sega followers has gone to Xbox platform because :

1 ) Nintendo was Sega former rival ( although I think that many Sonic fan jump to Gamecube and Nintendo platforms )

2 ) Many of them think that was Sony that killed Sega althought we know that was all Sega (financial ) fault.

3 ) Sega popularity was due to Genesis ( USA ) fortunes. MS is strong in USA. 

For the main question, I think that if Nintendo go out of business than almost all Nintendo fanatics will quit gaming ( atleast console gaming ) because Nintendo is a very different company than any other present nowaday in the industry. 

Nintendo famatics are very similar to Apple Evangelists , IMO.