Maybe not for hardcore gamers, but for the casual (or non-traditional) gamer, motion controls are definitely the future.
Problem is, if you sell a game like Wii sports to a non gamer, are they just gonna say, "I still like the first one, what do I need another one for?"
Once a year or so my mom breaks out the NES and plays Rainbow Islands for a week or two straight. She plays through it repeatedly, and leaves it paused overnight. I tried to sell her on the new one for Wii and she wouldn't even watch the trailer. She has zero interest because she likes the first one just fine and doesn't care what they might add/change. Would you say Nintendo and Taito have made a lifetime customer out of her? Hell no, she plays one game and hasn't desired anything more in the
23 years since. (now THAT'S replay value lol)
On the other hand. Modern Warfare fans probably went apeshit when MW2 was announced.
All of this is why I compare Nintendo to companies that sell treadmills, pedometers, and run amusement parks. Sure they're making a shitload of money right now, but I see nothing guaranteeing that market won't get tapped out because of lack of interest in "a little bit more." It's like a second video game market, because the people making it successful are a completely different set of people from the ones who buy traditional games. It's like we've got 2 video game industries, one for normal games, and one for waggle. The more developers focus on waggle, the longer it takes to get back to the real games.
Remember when Activision thought music games were a gold mine? They bough all sorts of shit up and pumped out an offensive number of music games. Now the genre has dropped in earnings and activision is firing off music game devs and trimming down production. Imagine if all that money and manpower had been put toward more traditional games, instead of a genre who's bottom was about to fall out.
EDIT:
http://fury.com/2010/02/jesse-shells-mindblowing-talk-on-the-future-of-games-dice-2010/Here's a interesting video from DICE 2010 about casual gaming. Somewhere around 8-10 minutes in he actually says that the key to a lot of these games is using "psychological tricks" to get people to spend money. Now I agree completely with the fact that all this stuff will make you shitloads of money. But I, as a long time gamer, have zero interest in most of it. Perhaps the world as a whole is just too stupid to resist a lot of this stuff? My friends werre obsessed with Mafia Wars at one time, but I saw a shallow text based game with no fun or interesting gameplay, and you had to pay real money if you wanted to advance much. My thoughts were, "fuck no", but it made a ton of money off people who went along with it.