Edit: It’s been brought to my attention that the animated viewport switching is actually in the 2.49 release. You can find it under User Preferences > View and Controls > “Smooth View”. I guess I never really noticed this until the 2.5 UI enabled it by default. I’ve been using Blender for the past 6 years and I still learn something new every day.
Something I didn’t notice right away until I started doing some modeling in 2.5 is the animated viewport switching. When switching in a 3D View in both Orthographic and Perspective, using the Number Pad 0, 1, 3, and 7 keys, the viewport is actually animated. It doesn’t matter what view angle you’re at either. The animation effect will move from any User view angle, even from a Camera view. This will be very helpful, especially for beginners, to understand where you are in relation to your scene and/or model. It’s great to see a lot of work is being done like this to help the user learn and understand 3D space and the application itself.