Logo/Watermark Removal
With Unity Pro, you can build a standalone Windows executable version of your game without the "Made with Unity" splash screen. Additionally, web player games will not display the Unity watermark when published with the Pro version.
Realtime Shadows
Unity Pro supports realtime self-shadowing shadows that just work. With Unity Indie it is of course still possible to use lower-end shadowing techniques, like Lightmaps or Projectors.
Fully Fledged Streaming
Stream in anything to the web player or a standalone application. Textures, animated models, complete or partial scenes, new missions and expansions, user-generated characters – yes, anything.
Unity Indie supports limited forms of streaming, like textures and music.
Render-to-Texture Effects
Image post-processing effects like Glow, Motion Blur, Color Correction and others? Check. Water with realtime reflections & refractions, and so on? Check. Other render-to-texture effects, like surveilance cameras, are possible in Unity Pro as well.
Video Playback and Streaming
Import and play back videos. Stream them from the net. Put them onto any 3D surface, or display them in 2D on top of your game.
Low-Level Rendering Access
Need to use custom rendering techniques, bypassing Unity's rendering pipeline? The Graphics and GL classes give you access to the bare metal.
Script Access to Asset Pipeline
Unity's asset pipeline just works in Indie of course. With Pro you can also directly access it from scripts. Need a build machine that churns out builds 24/7? It's just a few lines of code.
C/C++ Plugins Support
Have a custom native library that you absolutely must use? Use a C/C++ plugin to directly call into it.
... apparently.
In fact, I am using all apart from the assets features of these in my MMOFPS:
C++ for networking
Shadows for niceness
Streaming so we can change models, add missions, make effects prettier on the server and all client's get it updated (pretty mint!) automatically (obviously, otherwise it wouldn't be called streaming)
Render-to-Texture for post-processing
Video streaming to provide video advertisements in game (a bigger source of revenue)
Obviously, the watermark removal is needed for a game like ours.
Cheers,
Bozzy