Hi Mutantbc, The Amazon Mobile Ad Network currently serves ads to users who live in or are located in the U.S. We generally do not answer questions about future products or services, which this falls under. However, I'm going to move this thread under the Suggestions forum so it will be counted as a "vote for" such a capability. Thanks.
Count my vote as well. My apps target specific countries (not the US for now), so I implemented Amazon ads with a fallback to Admob only because I wanted to be in the Developer Select program. But I realized that the free impressions are worth nothing, because they will be shown only to the US audience.
I am pretty satisfied with the performance offered by Amazon Mobile Ads on the US market. I also believe support for other regions should definitely be one of your top priorities. (along with a decent reporting dashboard)