Depends on expectations. I doubt it's going to propel 360 to 100 Million plus consoles, for example.
Despite PR fighting talk, I believe Natal is seen by MS as bridging this gen to the next. They must know, looking at current sales and trends, that they have done really well in US, okay in Others and have made the barest of dents in Japan.
I believe Natal is about capitalizing on their position in US and gaining what traction they can with a broader demographic in that territory and establishing their brand and offerings ready to really try and expand on them next gen.
I see a lot of work from MS building around what they have and slowly altering the brand. I think they know it is really unlikely Natal is going to give them global domination, but I think they know that, in US particularly, it could put them both beyond reach of Sony this gen and in a place to compete for the 'casual' (if I can use that hated word) market next gen.
If it does that I don't think it will do below expectations. If it sells to a third of the existing install base and doesn't take hold with US market then I will see it as having failed to deliver.
It's going to be interesting to see what actually happens.
Try to be reasonable... its easier than you think...
