The one that caught my eye was the inclusion of experimental OpenGL hardware accelerated support.
For gaming and other computer graphics programs this is a big thing and means more games will work well on the Pi2.
At the moment it is still experimental which is why in the video below when showing the OpenGL demo a section at the bottom of the screen is greyed out. No ide a why (yet) as all works perfectly without OpenGL support enabled. This is a VGA monitor using an HDMI-VGA adapter where the config works perfectly without OpenGL enabled.
Below is a short video of the glxgears demo. First without OpenGL support and then with.
It's an amazing improvement.
With soft-OpenGL support it's really slow and there is a lot of flashing. With OpenGL enabled it looks great.