I want to be able to control which omega region blog entries (individual blog articles) are placed. They appear to be in the content-zone, but I have not seen how to control which actual region they are contained within.
All content ends up in the Content region. If you need something different, then I think g you have two options.
One, you can try to use a process function to move the content to a different region withing the zone. The function would be
function mytheme_alpha_process_zone (&$variables) and you would place it in "process/process-zone.inc". I have no idea if this would actually work, but it is worth a shot.