Music Unfolding has released M3, an Audio Unit plugin distortion effect with two wave shapers, two parametric EQs, a delay and an envelope/MIDI controlled formant wah section.
The wave shapers are defined with Bezier curves by clicking and dragging control points - it's easy to draw your favorite curve with M3 to achieve the distortion effect you want. Each wave shaper can be contoured using a collection of available filters. Because there are two wave shapers, the first can be used to drive the second. You can use the independent contouring filters of the two wave shaper sections to precisely design the character of the distortion.
There are two parametric EQ sections. Each EQ has five filters: low shelf, high shelf and three peak/cut. The first EQ section can be used to contour the signal before the distortion stages. The second is applied after the distortion stages and can be used for emulating cabinet response or adjusting the presence of the distortion.
There is a two-second delay with adjustable depth, feedback and filtering. The delay is placed between the two stages of distortion. The formant section can be set to auto-filter or can be controlled with a MIDI expression pedal. There are 90 different formant filter morphing wahs or oscillations.
M3 is available as a Universal Binary Audio Unit effect plug-in for Mac OS X 10.4+ and it costs $35. A a demo version is available.