I haven't read any of these doom and gloom threads so if I'm saying something that's already been posted, please forgive me.
Remember when the PS1 and Saturn launched? The best selling console that year was the Snes. Remember when the PS2 launched? The best selling console that year was the PS1. Remember when the 360 launched? The best selling console was still the PS2.
Nintendo now has two full fledged portable consoles on the market. One is still selling like hotcakes and the other has backwards compatability but the library isn't too enticing, yet. When the 3DS come into its own, it will do well. In the mean time, like pretty much every generation in the past, an established console with a great library of games, and a user friendly price is going to take the top spot. Right now, Nintendo is its own competition. This is nothing new and nothing that hasn't happend before. You guys aren't new to this, are you?
*this is all from memory, mind you. there may be a couple of exceptions......but I doubt it.*