To put it briefly, NAIAS organizers are not happy with Cobo's current condition. There is an expansion proposal, but it's still dead in water until an agreement is formed between the locals. There's even rumors about NAIAS leaving Detroit, although obviously the organizers don't want to. NAIAS at Detroit is still the biggest auto show in North America (hence the name), but many other auto shows have been stealing its spot light. Los Angeles has moved up its date to become the first major auto show in the season, and was one of the three places Bugatti officially launched the Veyron. Chicago, New York, and even Philadelphia had unexpected world debuts that would've normally happened in Detroit. Not only that, Porsche didn't even participate in the last NAIAS. I hope they solve this problem soon. It's still home of American Muscles, although I wouldn't mind even more world premiers at the Los Angeles Auto Show.
http://www.detnews.com/apps/pbcs.dll...65/1148/AUTO01
http://www.freep.com/apps/pbcs.dll/a...WS06/805310336