Very often we need to reduce the presets' intensity on some images. There are quite "complicated" presets not just with the basic sliders settings, but with custom curves in each RGB channel. When you start changing them manually, you can easily destroy the overall look (especially, if you are an amateur). I mean, changing the contrast and exposure leads to some color shift, etc. What about adding a special slider for changing the intensity of all the settings at once?
I've found this 3rd party solution, but haven't tried it.
http://www.capturemonkey.com/thefader/
ADOBE, can't you just buy this plugin and build in the LR?