Is this Advertising? Yes. Is it product placement? Maybe. Did Nintendo pay for any of this? (I have no idea—but I'm guessing no?). The Nintendo Wii has what the industry is calling Momentum. Nintendo's managed to create a product that is seems almost designed to generate buzz (in addition to what looks like a great experience).
Wii is everywhere. From videos of real people actually using the Wii, to blogs offering in-depth analysis on the Wii phenomena supports the idea that the product and marketing are closely linked—offer up a product/service worth talking about and guess what? People will talk about you.
PS, the Wii concept is really interesting—if you watch the videos you'll see that users get pretty physically involved—so this may be the one home video game that offers a variety of games which stimulate physical coordination in addition to hand/eye coordination. I'm really curios to see how this does in the market.