Michael Pachter, gaming guru and analytic, has told PS3center.net that he believes Natal will do a lot better on the market than the Playstation 3 Wand (or Arc, or whatever it will be called).
"Sony's internal development is top notch, so I expect the launch titles to be fun, and likely on par with Wii Sports for quality, but ultimately, I think that the motion controller will only sell to 20% or less of the PS3 audience, limiting it's appeal to third party publishers," he told the website in an interview.
"A year or so after launch, there will be 10 million [Project Natal units] out there, which will probably attract more third party support. Also, I think Microsoft will subsidize third party development to make it a success."
The reason for this difference, according is Pachter, is that the Wand/Arc/Whatever isn't an "in the box"-solution. Exactly who comes out the winner of the motion control war (I can't believe I just wrote that) remains to be seen when the two new controls are released.