I've just merged Benjamin Canou's new brightness applet into gnome-power-manager CVS. It's still WIP, but it looking good already.
Some sweet applet action…
If you've got a laptop without brightness buttons, you can now change the brightness easily. And yes, before anyone has a coronary, this is an applet and not another notification area icon, so you have to add it manually if you want it.
We have chosen to integrate this with g-p-m and not use HAL method calls directly as g-p-m is the policy agent. This means it's doing some clever things in the background – for instance dimming your screen when the computer session is idle, or changing your brightness when you are on battery power, and we have to be a bt clever when we try to change things manually.
Now, I've got no problem moving this applet into gnome-applets long term if desired, but for the moment the BrightnessLcd interface for g-p-m is not stable, and might change at a moments notice. You'll have to manually add –enable-applets to the gnome-power-manager configure line if you want to build this from CVS now.