In my opinion this article is a reworking of the truth. MS will release a "360 Natal" as it would be stupid not to bundle Natal will consoles once it is released to guarentee uptake. However MS will not release Natal (next year) with a more powerful 360 unit as they know this will piss off their core userbase who have bough both the original xbox and the 360. What would not surprise me is if they announce - prior to the release of Natal - that their next generation xbox console will be backwards compatible with the 360 iteration of natal so if you buy natal for the 360 you can just unplug it and plug it into the 720 when it is released in 2011 / 2012, after all Natal is really more about the incredible software that powers it than the hardware inside it and MS are great at updating the xbox software.
tbh as long as Natal as a technology gets good reviews i'd buy it however it was packaged / bundled and whatever the cost... but then again I am not the "new" market MS is trying to tap up with Natal.