Google Gadgets can now be added to your calendar. Previously the only gadgets I had on my calendar were Google Doodles, Weather, phases of the moon, and PicasaWeb Photo of the day. Now just about anything is going to be possible. I briefly played around with it this morning and added horoscopes and Sudoku to my calendar.
Other new gadgets include Movie Release dates and famous people's birthdays. I expect that very soon there will be video game releases as well. Documentation is out for the gadgets, so get coding!