Here are some of the details of the integration with Google Calendar:
* Tasks that have due dates will automatically appear on your calendar in the All Day event section.
* To create a task with a due date in Calendar, click on an empty space in Month view or in the All Day section and select the Task option.
* To attach a due date to an existing task, click the right arrow next to the task in question in the Task list. Then, click on the calendar icon to select a date.
* To modify a task's date, simply drag the task to a new date (as you would with a calendar event).
* To mark a task as complete from within Calendar, click on the checkbox next to the task.
Unfortunately, you can't use "quick add" to create tasks, the tasks calendar can't be synchronized with other applications and you still can't receive email or SMS notifications for tasks.
{ Thanks, Daniel. }