Do you mean the casual crowd as in the crowd who already own 360s (many casuals do- they consider themselves hardcore but they're not), or the "casuals" that the Wii appeals to? If the latter, you're setting yourself up for massive disappointment. Because they're too busy playing their Wiis.

If Microsoft were to launch Natal next generation, that might make a significant difference. If it was bundled with the console. And thus completely ruined it. You do need buttons and D-pads and analog sticks for some experiences, and Nintendo remembered that even when designing motion control. To be honest, there isn't a lot you can do with "voice recognition" and...for lack of a better description, waving your arms and hands about. Certainly, it would work in some games, like the 3D breakout that was demoed, or maybe some mini-games. But let's have a look.

SHOOTER: Okay, how would this work? Perhaps you point your finger to shoot. Okay. How do you move? Reload? Change weapon? Jump? Take cover? Crouch? Roll? (unless you're planning to do a forward roll into your TV).

FIGHTER: We've all seen the cute little ad from E3 with the guy doing a ninja kick against the kung fu master. Seriously? Do you really think people are going to punch and kick and slide like in Tekken or Soulcalibur? And what about special moves?

RACING: We saw this to a certain extent with Burnout Paradise on...was it Jimmy Kimmel? (celebrity endorsement, of course). He steered very accurately. He was also going extremely slowly. How would he boost? Brake? E-brake? Change to rear view? Reverse? Change gears?

In fact, I'd like to know which games currently available on 360 could possibly work with Natal, and failing that, an idea of a good, deep game, that would work solely with Natal.

The best case scenario I can see for Natal is it becoming a secondary mechanic, like Sixaxis. You are playing Gears of War 3, you select your grenade, raise your arm, and throw. It can't be used as a sole control method like a gamepad, Wiimote+Nunchuk or, now that I think about it, a PS Motion (depending on what the PSMotion ends up looking like).

To summarise that relatively long post, Natal doesn't really have that many practical uses in gaming.

I believe they said the price would be "under $200", and that's the last official word we had. There are rumours of it being bundled with 360s (or an entirely new console which happens to have the same hardware), but those are only rumours. It certainly wouldn't be the same price as the current 360 because a piece of technology as (admittedly) incredible as Natal would take money to create. If the PS Eye is $50 (right?) and Natal is so superior in every way, surely it should be at least $100?

It could sell if there were conceivable uses for it, but have a look at my other post and see if you can tell me what exactly Natal would work with.

I think your looking at the Natal and Sony's wand in the wrong light.  They don't have to be geared toward every game made.   I am 99% CERTAIN microsoft isn't stupid enough to leave out an actual controller pad in their next console or in the new Natal 360.  Nintendo has an entire lineup of games that work well with its motion sensing and this has completely taken it to Sony and Microsoft this gen.  To simply write off its success or appeal to people is ludicrus. 

If Natal works properly and there are a few good titles when it launches, it will be huge.  I can see microsoft completely ripping off Nintendo's entire lineup and making it work better.  Just like they did for windows.

I understand that, and if Microsoft releases their NATAL 360 with no controller, they are doomed to failure. The problem is, while I can think of uses for the PS Motion (since it's basically a Wii Motion Plus but more accurate and with a coloured orb!), I can't think of many for Natal. There's the usual EyeToy stuff, and EyePet, but really, what can NATAL do that the PS Eye can't? That isn't a rhetorical question, I really do want to know.

Kantor quote "The PS Motion won't do any better. Actually, it'll do much worse."

So, if you can't think of any uses for Natal, why do you think it will do better than PS Motion?  It will be a full functional motion control device.   Which should be able to do nearly everything Nintendo or Sony's can do Pluss so much more.