1. Obviously you've seen by now that that the icons are no longer displayed on top, they are on sides.
2. Many of the game features now happen in a popup, messages, actions etc. The popups can be closed by clicking the close button, but also by pressing the Escape key. Esc key will close the last popup. Note that the quiz popup will not be closed by Escape and also does not have a close button, since it is a special popup.
3. The stable has been changed to allow easier access to your horses. The tabs on the left side allow you to easily find your horses by gender, by whether they are or not hungry etc.
4. The market, jobs area, arena, barn, workshop - they were changed to make them easier to understand and access.
5. Colors can be still changed, they just are changing different things. You will see that changing colors changes the gradient on sides.
6. Friends were changed to make the area a bit more visual. You can also import the custom colors of your friends (if they set any).
7. If you have a wider monitor, you can switch the game to a wide mode by selecting I want to >> Change >> Screen size. That will switch the game between regular mode and wide mode.
8. The logout button was replaced by the close image in the top-right corner of the game window.
9. At the market you can auction credits now. Just like you did with horses, you can now sell or buy credits.
10. Clubs and "goals" have been removed from the new version. The "goals" completely, the clubs will probably be added later under a different form.
11. The forums, quizzes and blogs are now accessible from the Town Hall.
12. A lot of icons have been changed, the areas in the game were made so that they look and behave in a similar way.