I'm working on exactly this but specifically for photoblogs. It will be a hosted service that picks up new photos from a Dropbox directory, generates thumbnails

I'm working on exactly this but specifically for photoblogs. It will be a hosted service that picks up new photos from a Dropbox directory, generates thumbnails, uploads to S3 and creates a draft post based on the EXIF data. I can then use the web-based admin interface to publish the post on S3 which will do all the heavy lifting of actually serving the blog pages.