Monty, seriously, drop the Mexico thing. There are very little, if any consoles sold in Mexico- any that are would be imports from the USA and have already been counted as the man has said.
It is a traditional rule of thumb that has been used for the last 20 years that
NA ~ 1.1 * USA NPD
It works for every other console and software title out there, and it has also been common to have 2m+ units unsold just after christmas. Shipments before are always huge and then pretty small for the first 3-6 months of the next year.
Personally I don't see how Xbox360 can be over 5 million NA at this point, never mind the sorts of figures you are suggesting.
I think someone made a good point that if vgcharts is arriving at the figures for all 3 consoles using the same methodology then how can they be accused of being biased? If they take the same raw data from the same sources and do the same calculations on it to get the final figure for all 3 then how can they be any fairer than that?
Can you show me where Mexico accounts for zero sales? Also, I'd be interested to see where you're getting the 10% figure for all of NA minus the US.
What I do know is that MS had an official launch in Mexico, Mexico is listed as a "significant" emerging market in video games according to Wikipedia (http://en.wikipedia.org/wiki/Computer_and_video_games).
Heck, MS just had a big launch party in Mexico for a single game... Viva Pinata... in which they attempted to break the record for the largest Pinata ever. Does this sound like actions that a company would do for a market that sells ZERO consoles? Hell, no...
All of you people just tell me to "forget" Mexico and that it sells nothing... that simply isn't true, and unless somebody can back that up, then I'll keep on...