Being that I think there are many people who will bring in up anyways, I will stay away from talking about how the technology may not be as mature as it needs to be, designers may not be ready for the concepts that need to exist, or how people might not be able to psychologically handle a "Controller Less" game yet ...
There are many factors people who like to hype Natal don't want to consider which can have a very negative impact on its sales potential. One of the major factors is the timing of the release, and without even considering that it is a late generation add on and those (historically) have performed very poorly, there are many reasons why this is a problem. In 2005/2006 the release of the XBox 360 and pending release of the PS3 alienated many gamers because the price of the consoles was (insanely) high and they were only focused on a very narrow selection of games designed to appeal to the "Hardcore" demographic. When Natal is eventually launched Nintendo and Third party publishers will be delivering more content which is targeting this broad demographic of gamers in a month than Natal will (probably) be able to release in its lifetime ... These gamers are not being ignored anymore and have little reason to feel alienated which makes it dramatically harder to convince them to switch consoles.
