Well, it may very well have been brought to Europe already, so Italy isn't necessarily safe. This is where things get interesting. The students from New Zealand who returned from Mexico on a language learning trip acquired a flu-like disease that is confirmed to be Influenza-A, which puts it in the same category as the Swine Flu, but more testing is required to confirm that more precisely [Swine flu is influenza A/9].
Did they acquire the disease from pigs? Probably not. Unless we are told that the students toured a pig farm on their trip, we have to assume they got it from human transmission. It remains possible that it is another flu altogether that they caught, but...
How did they return to New Zealand. The only obvious answer is via plane. Which means that they passed through an international airport. If we are generous and assume that they got a non-stop flight, the possibility remains that several passing people in that airport and definitely in that plane were exposed to the virus, and carried that elsewhere.
If we confirm that the strains in Europe, south America, and New Zealand are Mexican swine flu, it becomes obvious that the only possible origin point for the overseas cases is some international airport in Mexico, and then, other international airports around the world. Becuase International airports interact with each other through very few degrees of separation, they behave as if they were directly adjacent to each other.
Basically, what I'm saying is that if any one of the over seas cases are confirmed to be the Swine Flu, the probability that the other cases being the swine flu increases a great deal.
This becomes further complicated by the concept of carriers. For some people, even many people, the virus may make a person fairly miserable without ever being a threat to that persons life, and may not even interfere with that persons day to day activities. While the virus itself remains just as virulent, it does not present itself as such in carriers.
This is why the number of reported cases could be far lower than actual cases.