MR support in Maya2009 is spotty at best. After some experimentation I've concluded the mia pass material can output direct light, indirect light, reflections (pre-multiplied), specular, AO, and zdepth. These passes will also work with a FG lighting model.
However, there is absolutely no support for global illumination - the renderer becomes bogged down in a seemingly infinite render. I even tested it on the Render Rocket render farm and had to concede defeat and abort it. To work around it, I had to manually set up the pass materials and scenes. A week and a half later, everything is rendering fine and speedy (at least for me).
A total of 34 final render passes:
BG (1 shot complete, 11 remain)
color
ambient occlusion
direct light - blue, sun, red, led
indirect light - blue, sun, red
raw reflection
reflective mask
reflective ambient occlusion
specular
glass
glass mask
color index
depth
CHRIS (1 shot complete, 11 remain)
color
ambient occlusion
direct light - blue, sun, red, led
indirect light - blue, sun, red
matte shadow
raw reflection
bg reflection
reflective mask
reflective ambient occlusion
specular
lens - inner, mid, outer
lens mask
motion vector
color index
depth
JEANNE (0 shots complete, 7 remain)
film plate
matte shadow
bg reflections
chris reflections
LAUNCHPAD (3 shots complete, 0 remain)
beauty
ambient occlusion
depth
