Yeah, I'm not worried insofar as we will still have traditional gaming. What worries me is that feels like the hardware side of the console industry flailing around spastically looking for the next 'big thing'.
Think about it. You develop the X360 and sell as many as you can. Some time in the future you will make another console, but you can't make it too early, or people will complain about their current console becoming obsolete. So you're stuck in a kind of limbo. Your sales slow down as most people who want your current gen console already have one and it's too early to launch a new one.
So what can you develop to stimulate sales ? Answer : gimmicks and peripherals. And does it work ? Nope. Look at the EyeToy for PS2 as one of many, many examples. The only thing this has really worked for is instrument games like Guitar Hero and Rock Band.
My prediction is that this will die in the ass. People with X360s and PS3s generally deride the Wii and I don't think this is complete fanboyism. I think that a lot of these gamers, like me, genuinely don't want to fuck around with motion controls.
I'm never one to panic when products I don't want are launched. It's not going to have a negative effect on the things I like - developers aren't going to stop making traditional games in favor of this bullshit. And six months in, I'll be surprised if anyone is developing for it.
Uberprediction - massive failure. But I've been wrong before. Once.