Also, keep in mind, those countries that are a border and a name. . . are a ripe play ground for your own game to set your own rules. Don't like how politics runs in Seattle? Pick a po-dunk city in the CAS and use the four pages of description in the Almanac as a loose framework and go to town. Right now, my group are stomping around the Norfolk sprawl (which has a total of one official paragraph written about it in SR4 books that I've seen).
It helps that we live there and I like world building, but that doesn't have to stop anyone. It's an alternate timeline with magic and insane technology, you could pick Nashville and decide that with the influx of magic, the King is back as a Free Spirit who's decided to make himself the mayor-for-life. His policies have put him at odds with state officials, but his local popularity and international fame make it difficult for them to move against him.
Don't get me wrong, I'd love to see sourcebooks for the cities you've mentioned, and the corporate locations books previously discussed make great pdf booklets that I would go after like a fat-kid in a candy store. I'm just saying that if you're GMing and a blank spot on the map irritates you, you're looking at it wrong. It's not information you're missing, but rather an invitation for you to put your own fingerprints on the Shadowrun universe in a serious way.