If their software remains just as brilliant, yes.
The problem is, that brilliance is usually tied to the software's tailoring to a specific hardware, so if they went multiplat I worry that they'd lose a big part of their spark.

Yes I would. As long as they keep making god games, I'll keep playing them  - regardless of the console they're for.

If Nintendo was a third party...we would have Gears of Zelda and Call of Mario...

Why because I would take an agressive move against Sony? This was their best opportunity to do so with Sony and their financial woes atm. Last gen I would not consider such move as everyone expected PS3 to dominate. 

Nintendo on a different platform? Playing Zelda with the Dualshock form factor (that I hate)? Having to stop playing my Mario because the console RRoD'd (instead of working flawlessly for a decade like a GC)? Not having the best (IMO) controller every generation? Nah, I don't think so.

Luckily this won't happen. Even if the Wii U fails (which it won't), Nintendo could survive on the goddamn 3DS alone.

I'd be more of a fan.

I'm a fan now, but not a supporter. I haven't bought a Nintendo title since the SNES.

However, if they became a Multi-Platform developer, there'd be several titles I'd be looking to buy, either on the 360 or PC.

Their nasty, gimmicky, child-like hardware is very off putting for adults like myself, so sadly I won't be buying any of their games.

Yes. But it would be a very dark world for gaming. Someone put it best when they said "If it was only MS and Sony, that'd just be boring."

Sorry.....but everything you just said reeks to high heaven of absolute BS.

It's one thing to say that you're on a budget and just can't afford to buy Nintendo consoles on top of the GREAT 360 or PC you already own. But it's another thing entirely to call yourself a fan but not have bought a single piece of Nintendo hardware or software since the SNES era. Sorry, but that's not a fan. You can't really call yourself a true fan of something unless you actually show it SOME measure of support.

And that entire last line about their "nasty, gimmicky, child-like hardware being off-putting for adults like yourself"? Reeks of THE worst, and LEAST adult-like kind of childish, petty fanboyism I've ever heard. Mature, adult gamers play GAMES, and enjoy them, regardless of what they are. If you think something is too "child-like" for you to bother being seen with, you have a problem. And quite frankly, you've been missing out on a LOT of great gaming over the last several generations, home console and portable. Your loss really.

Sorry DevilRising, you arrogant little prick. I answered the question and gave my reasons. I'm a fan, not a fanboy, hence why I don't own any Nintendo consoles. It's my honest stance, not bullshit.

I'm a Nintendo fan, I hope they do well and I with them luck. However, I won't be buying any of their titles unless they go Multi-Platform, do you understand?

User was warned for this post - Kantor