Google just made the lives of third-party calendar developers much easier. Rather than having to constantly poll Google Calendar servers for updates, the Calendar API now supports push notifications.

Google has made a small change to the Google Calendar API that nonetheless could make a huge difference for developers and users. The Calendar API now supports push notifications - alerts sent ...

Google Calendar will be losing a few features, Google Sync will be axed (on the consumer side), as will Google Calendar Sync, SyncML, the Issue Tracker Data API, and the Punchd app.