While competition in the console space is at its fiercest, history has taught me to not count out Nintendo. They have innovated time and time again in the face of extreme competition, and I expect them to be deal with Apple accordingly.
I agree $299 seems like a steep price point for the 3DS, but if the technology is as impressive as we have been lead to believe by the tech/gaming press...the launch price may not be as ridiculous as we think. Regardless, they'll be targeting early-adapters at launch.
Also, we know a new Wii is on its way...its been heavily speculated for sometime now (http://wii.ign.com/articles/113/1136075p1.html).
Overall, NTDOY in my mind is still a long-term buy (with emphasis, on "long-term").