Brightness slider - will it be available in WP at least by 2015?

When can I get a brightness slider in WP? Just annoyed that MS cannot implement this simple functionality till now. Even Nokia can implement this in no time in the 'display + touch' settings area.

I find the 'low' still brighter than I want and automatic only works well in a room with/without a constant light source (annoying when traveling and the street lights can make automatic brightness go wonky).

And will be very useful for my precious battery life.