I frequently come across a reoccurring question in the MSDN forums. The question usually looks like the following:
I don't see my country listed for the Marketplace, how can I register so I can sell my apps?"
The answer to that question is "You can't." It is sometimes followed by a question about trying to register within another country. I don't think that will work; when I validated my identity for the Marketplace it was against a government issued ID, a bank, address, and one of the national credit reporting agencies was involved in addition to a notary. I wouldn't have been able to validate against all of those things unless I had residency in another country. So there doesn't seem to be a way to circumvent that. HAving hit that brick wall the usual response from the would be Windows Phone 7 developer is a rather emotionally charged statement declaring that Microsoft needs to get it's act together and ad their country.
One might wonder why those other countries are not yet able to access the Marketplace. At present there are 31 countries that have access to it (at launch it was 28 countries). Why can't Microsoft just add the other countries? Answering that question requires that one knows what's involved in adding another country. Unfortunately Microsoft doesn't disclose its commercialization processes nor everything that it does to add another country. What is known is that when a country is added there's matters related to tax treties and international trade, identifying local decency standards, establishing agreements with carriers, establishing agreements with a financial institution that takes care of the deposits, agreements with content providers, and so on. Adding a country requires that Microsoft do more than just add another name to the country drop-down list.
As things stand right now Apple has the largest footprint for their online Marketplace covering a total of about 90 countries. Microsoft is in second place with 31 countries (though it is less than that for Windows Phone 7), and Android is in third with 11 nations for paid apps (but 46 if you want to distribute free applications).