6 days ago a new version of SimpleFont was realeased, and as i can read on the site, while i have also tested the demo version for a few minutes, it can create "super pixel fonts". It has some very productive tools as it concerns creating "gray pixels". It has a "draw superpixel element" brush with percentage settings (how much of the whole pixel will be filled) and an "erase superpixel element" tool...
http://www.font-editor.com/tutorials/creating-super-pixel-fonts/
Very interesting for those who create (super)pixel fonts... although i'm afraid that it's a bit confusing as it concerns Unicode indexes and the ability to add many ranges in one font.
On the other hand i really like the real preview on the small "Glyph cells" where you can see how each character would show up in PS or Flash, even with gray pixel too, and how "dark" each percentage setting of subpixel elements seems.
:o)