Image Credit: Twitter
Twitter's Calendar of API Changes Page is not meant to be a replacement for the Developers Blog or @TwitterAPI when it comes to important API and platform announcements. The page is essentially a roadmap for important dates related to Twitter APIs and the Twitter platform.
Twitter has made many changes to the platform in recent months including sunsetting API v1.0 as well as the @Anywhere service. The Calendar includes deadlines for the sunsetting of these services and links to blog posts and announcements.
Visit the Calendar of API Changes for the complete, up to date list.