This is quite obvious, as the N9 wasn't actually launched/officially offered in the US at all.

In South Africa (which got the N9 quite soon after other countries, launched in late Oct 2011), the N9 is advertised in all Vodacom and MTN stores. The N900 wasn't really officially available here at all (one Vodacom service provider did offer it) and not advertised at all. Whereas In Nov/Dec, Vodacom's handset booklet had the N9 on the front page. I am not sure how good sales have been, but I have seen a number of people with them (whereas I haven't seen one other N900 here).

The Lumia 800 was launched exclusively on Vodacom last week, I am hoping this will result in sane prices for the N9 (Vodacom's prepaid price for the N9 is about 10% higher than that at the Nokia store at Vodaworld ...).