Next-Gen Roto Brush, I have been looking forward to, the 3rd generation, and hopefully the best and most powerful version to date.
OpenColorIO Workflow enhancements is welcome as this is an industry standard and After Effects has always lacked color options.
Text Scripting Support should be an interesting addition to make more powerful text animations.
And Currently in the Beta
True 3D Workspace should be pretty awesome, since Adobe does have it’s own 3D software (just wish it was part of the same subscription).