Contrary to what you may hear from sources who fire before ready and aim, Post Formats have not been removed from the core of WordPress 3.6, which is due to ship any day now. Only the new User Interface for Post Formats has been removed. My take from lurking around Make.WordPress.Core: The development team decided that the new user interface was too prominent for a feature that is still too little-known and too little-used. They feared it might have confused many users. I happen to agree. By the way, this WordPress blog post has been categorized as “General”, tagged with “WordPress” and “Post Formats”, and assigned the “Aside” Post Format.