The fact that this short film will be available soon on iTunes internationally is great. But I'm more curious as to why there is a problem releasing this kind of content internationally at all. The distribution platform is already time tested, has the bandwidth, has the purchasing capabilities and is a more or less solid internationally available application. There also shouldn't (as best I can tell from the blogs) be any studio license issue involved either. From my point of view, there is nothing actually 'new' happening here at all as was previously claimed. 

So put simply why is there an issue with getting iTunes content distributed worldwide?

The only obvious reason that springs to mind is re-rating the film with country specific classification code. As this might involve a committee and need to be slotted in for viewing amongst with other content.