I would like to have a chance to add to mostly all colour correction filters switcher to light/mid/dark area. The nice try in color balance tool and selective collor. The same should be done for saturation, vibration, brighness/contrast and etc. It's provide more powerful control.
I'm using Photoshop and PhotoLooks plugin. They have wonderful tone with a 3 color regulators for low, mid and hi colors range. I think it's a really cool to be able to do the same for Vibrance (if I want to apply it only to the mid tones) or to Hue/Saturation (if I want to shift only bright area). It's really needed. I do some post effects and some time I need to shift color or desaturate only dark area. I can do thousand clicks or just by select "Shadow" in HUE/Saturation filter.