I agree that it's far too early to be making assumptions. Unlike Sony and Microsoft, Nintendo doesn't give their plans a year in advance, so there's no telling what Nintendo has in store. All I know is that both Sony and Microsoft have very little in the way of system sellers to keep momentum, so for them to keep momentum they will need to do yet another price drop later this year, unless they somehow don't botch their motion devices' launch. PS3 Slim's momentum has faded, and the 360 is in trouble as Sony starts eating at Microsoft's lead.

If I must give an answer, I would say probable. It depends on one fact: can they deliver on their delayed Motion+ games and the Vitality Sensor?

Don't think so. Then again, never say never when Nintendo's involved.

It matters if the Wii will surpass the PS2!

And I do think it will reach 50%. Holidays 2010.

@OP:
The latest news about Natal http://www.vgchartz.com/forum/thread.php?id=97288&page=1 , if true, makes this less unlikely...

2 year bump! (permission -_-)

http://gamrconnect.vgchartz.com/thread.php?id=138611&page=1#

Interesting 2 years ago people thought 50% was obtainable, but now it's looking at sub 40%

To be fair, the ball was in Nintendo's court, and no one could have predicted how much they ended up dropping it.  It was a reasonable prediction at the time, really.

I think the one from 2008 is better: http://gamrconnect.vgchartz.com/thread.php?id=54177

90% of posters were adamant Wii would reach 50%, some said 60 and someone even 72.

Ah! That CrazzyMan.

 4 million each fiscal year! 

Because they're HD and it's easily distinctive. Adding Wii and DS is just stupid and doesn't make sense.

FYI Nintendo are not printing money right now, Microsoft is the only one with a profitable gaming orientated division at the moment.