Having owned a Wii since launch I guarantee you the novelty of that would wear off fast.  As soon as your arms start cramming.  It's great for short bursts (Wii Sport Resort) but for hours on end?   We'll see how Red Steel 2 fares.

Most traditional games were never intended for motion.  Some sports titles work well and surprising sandbox games really benefit but for pretty much anything else, traditional core gamers will very quickly lose their interest in Arc (or Natal) and go back to the controls they grew up with to play traditional games.  I've heard so many people complain that dual analog is better for FPS than Wiimote but that's just because they can't aim, but they have years of practise moving an analog stick.  Arc will have the exact same issues.   That is why Nintendo never focused on winning over that crowd in the first place.

Sony and microsoft have already won that crowd. They are trying to each take a bite out of nintendo's pie now. Thats why they are doing this.

Oh I get that.   But I don't see them having much success there.   Few casual gamers will become multi-system owners.  And if you're a casual gamer (I hate that term) looking to buy your first system  Wii has a far, far more extensive library of games for you, is cheaper and doesn't require additional purchases for motion control.   

If that's the target market then using DS3 as a nunchuk is a MASSIVE mistake.  The wiimote is designed to look as unintimidating as possible.  It's made to look like a TV remote.   That's why Nunchuk is totally seperate and optional, so as to not scare away people who 'don't get' current controllers.    If you give them an Arc and then say, but you still have to use this controller with a gazillion buttons and knobs, but with only one hand now, they'll be immediately turned off.

Natal has some merit as it'll be seen as entirely new but Arc screams 'me too' 'Wii clone' to the casual observer.    Where Arc (and Natal) may succeed is in getting the wives of current owners to use PS3's (360's) and buy games like EA Sport Active and probably Boom Blox.

In the end, it'll all depend on the 'games'.  On that front I'd give Sony the edge over MS as Sony knows how to make games for non-gamers.  MS doesn't.

I have news for you. EVERYONE gets current controllers. My 5 year old cousin picked up my PS3 controller and within 10 mins he understood how to do everything in the game he was playing. To say a simple controller(to which the design has not changed since ps1) is confusing for a casual person is wrong. 

Also There are many people who are still last gen owning a PS2 that are going to be looking to upgrade soon. THOSE are the people they want to capture. They know they cant steal any from nintendo. But its as simple as this. right now

game A = shitty graphics motion controls

Game b Good graphics no motion

"Wow swinging my arm around looks like fun"

What it will be is 

Game A has shitty graphics and motion

Game B has good graphics and motion

"Well clearly i will get more from game B seeing as its much prettier then A and I can still move my arms around, that looks like fun"

People who buy the Wii either A love nintendo and know what they want. Or B know that it has motion and knows nothing else and buys it. So if the other two companies get motion. Nintendo losses its ENTIRE thing. PS1 -= CD it won. PS2=DVD it won. PS3 = bluray(would have won IF motion was not "cooler" to casual players. So right now its Wii=motion=win. Do you think the PS1 would have done nearly as well if nintendo was suddenly able to give their N64 CD support? I doubt it.

Thats exactly what I meant.

I agree, im not a fan of an improvise solution as well. But theres some major advantage of this tho, you dont have to purchase another controller. And you have the sixaxis integrated with the "nunchuk" + some button that are easily accessible. I think they should offer both, this method + another controller that would do the same thing but designed in the "right" way. This would be a very good marketing to offer both. It would permit to offer Arc at a low entry price. Like Arc controlller + eyetoy for 49.99$ or 59.99$, and then mod their software so you can use the dualshock in the manner we talk about. Or you would also be able to purchase another dualshock that would be design like the "nunchuck", but with buttons and sixaxis for 39.99$ or 49.99$.

I agree on that one, motion is more suited for casual play, at least up until now. Now, if Sony were to bring many titles like heavy rain using motion controls it could be a different thing. I could easily play for a couple of hours on a heavy rain type game using Arc. But thats the only thing I can think of. All the other mini games and sports game sure are for casual play. And most of the other games that use it, like adventure games or racing games, youre better off switching to regular control if you intend to play seriously. Its more precise, faster and effortless for the arms. Between, im not talking of the Wii in this whole paragraph, many PS3 games offer some kind of motion control already.

wait, when is GDC ?

I'm going to wait and see more before I judge.

Kids are like sponges.  Try giving the controller to your grandmother and see how far she gets.   But Wii's have become a staple of retirement homes.

Your completely wrong in your assessment.  If superior graphics and gameplay mattered to that audience Super Mario Galaxy and Brawl wouldn't be getting their asses handed to them sales-wise by New Super Mario Bros Wii and Wii Sports Resort.

Accessibility and fun matters to them.   They do not view the current controllers or HD games in general as accessible (or fun).  I'm sure Sony will launch 'non-games' with Arc but the Wii now has 4 years library to compete with.   All the casual games that PS2 had, have ignored PS3 in favour of Wii for the most part.   You don't see Deal or No Deal, Hanna Montana or even Crash Bandicoot on PS3.   That hurts the PS3's appeal to that market.   Wii has a huge variety of exercise programs, PS3 will likely have one or two (Sport Active, Your Shape), which will also be on Wii.

Sony's best chance is to make games people want to play.  The pet game looks to be in the right direction but it'll have to compete with whatever MS is doing on Natal and Wii Sports/Sports Resort/Mario Kart/NSMBW/Wii Fit possibly Wii Vitality and Wii's immense casual library which is also dirt cheap.   Graphics will not influence casual / non-gamers buying decisions (much).

Sony stole the market from Nintendo with PS1/2 by expanding the market, they targeted teens and adults and painted Nintendo and Sega as the kiddie systems.  That had more to do with their success than CD (which did help).    Now Nintendo has reversed the situation by expanding the market again to girls / women and older adults and allowed Sony and MS to paint themselves as 'core' systems.   It'll be hard for the HD systems to now break that mold.  Most especially Sony who spend the first couple years painting PS3 aggressively as the ultimate core gamer system.   MS has been softening it's image over the last two years (cutesy Avatars, simplified XBL, Lips, Buzz) and is better posed to win casual gamers.  It's also cheaper which helps - although no pricing on Natal yet.