I think some people have a country they want to go to for various reasons and then find a project or do ETA in that country. Others have a specific project in mind and then find a compatible country in which to work on the project. For me, I fell in love with the Middle East when I was there this summer and wanted to go back to learn more about the people and the culture there. I found a really awesome project too, so that made the decision to apply obvious. Though, who knows what they will think of my application...
As for the Arab/Gulf countries,....I looked on the spreadsheet and they usually find out by the end of April, so it could be next week, insha'Alla