Not to point to the obvious here, but the US lags behind Europe (esp. UK) with respect to mobile broadband usage (or so we are told). Hence why the iphone sales in europe were much better once the 3G version arrived.
I reckon it is more likely to have an n900 then an n910x when whatever x is (looks like it isn't wimax) given in europe the investment of the 3G infrastructure the providers have.
(I believe that the old iphone caused problems because stations had to be retrofitted with edge technology, when they were already HSDPA (or what ever 3.5G is, I get confused with all these names!)