@Grimes : I disagree completely then. PS3 will always sell a lot more in Europe + Japan (total : double the hardware US sales this week).
The fact that the #1 market is still (but not by much) the US doesn't mean every product should consider it as the most important market. Some products sell more elsewhere and are perfectly fine with it.
If anything, 360 needs a lot more succeeding outside the US than Sony needs to succeed in this sole country.
In the end, what matters is WORLDWIDE success, nothing else. Hence the stupidity of a single country analysis.