1) How soon is it needed? Something that is crucial to the early design/development of a game gets a higher importance than something that can be "tacked on" later.
2) How hard is it to add? We all know Niko is busy and has his own plans for what he is going to be adding to the engine. So features we request must also be reasonable for him to add. Things that I thought would require alot of time got slightly lower importance simply because its unreasonable to demand such things

REQUEST: 32bit Indices
IMPORTANCE: Low
COMMENT: These would be nice for prototyping without having a map partioning system built. (ie allowing you to "throw" a huge raw heightmap at the engine)
REQUEST: MD2 Size
IMPORTANCE: Moderate
COMMENT: I haven't had time to mess with 0.3 much at all. But I'm pretty sure the MD2 meshes are still taking up a 4-5 times more memory than necesary. I know its not an easy things to fix, because of the way the irrlicht is laid out, but I think its needed in the long run.
REQUEST: 8bit Alpha Support
IMPORTANCE: High
COMMENT: I ranked this of high importance because I feel its a crucial part of design. The use of 8bit alpha channels for texture blending on terrains is important IMO.
REQUEST: Shaders
IMPORTANCE: Moderate
COMMENT: A very powerful feature, but one that will most likely require a good deal of work. Thats why I put it as moderate.
REQUEST: Fog
IMPORTANCE: Moderate
COMMENT: Useful (if abused) effect. Hard to find a game these days that doesn't use atleast a little fog. Far better than letting the Far plane saw off you distant mountains

REQUEST: Directional Lighting
IMPORTANCE: Moderate
COMMENT: I tried using point lights to do some simply lighting on my outdoor enviroments, but they just didn't seem to be what I wanted. I think directional lighting would be better.
REQUEST: Projective Texturing
IMPORTANCE: Moderate
COMMENT: We've all seen the cool effects it can produce, some sort of easy to use Projective Texturing would be great.
REQUEST: Occulsion Culling
IMPORTANCE: Low
COMMENT: HArd to do, but definintly and great feature to have. Even if it doesn't get added until after 1.0.
REQUEST: Frustrum Checking
IMPORTANCE: Moderate
COMMENT: A way of telling whether or not a 3d Node is in a given camera frustrum. This would be helpful in networked games by limiting data sent back and forth.
REQUEST: Follow Camera
IMPORTANCE: Low
COMMENT: A simple Follow/Third Person Camera included with engine would be an easy enough addition when there is time.
REQUEST: 24bit Textures
IMPORTANCE: Low
COMMENT: Nothing urgent about this, but it certainly would be good to have a full range of options when it came to texture color depth.