Some possible suggestions:
- the ability to align selected objects to first object selected (top, left, right, bottom, center...)
- more procedural textures
- a variable noise texture
- the ability to select multiple objects and assign materials or textures simulataneously to all those objects
- random vertice selection under Specials menu
- add noise function to Specials menu
- make noise button variable (like fractal subdiv function) in Edit window
- new object constraints: copy Size (or individually Size X, Size Y, Size Z)
- increase nor intensity range values in materials window
- ability to edit object (when pressing "/") as if it were not rotated (temporarily canceling rotation for the purposes of editing an object)
- prompt to save changes before exiting Blender
- crash recovery option (reload last temp .blend file if possible)
- render level options: render as grayscale, increase/decrease RGB levels of rendered image/frame, hue/saturation adjustment, brightness/contrast, camera grain, color correction, DOF, blur/sharpen (some inline post-production stuff, especially handy for animation purposes)
- new primitive shapes: pyramid (3d triangular), mesh donut
- add new mirror x/y options to image textures to create continuous/seamless textures when repeated over a mesh
- add Make Dupliverts Real (ctrl shift a) option somewhere in interface (maybe Specials menu)
- new palette option/window when double-clicking mirror/spec/color boxes - creates a color selector palette with user definable boxes and a save/load palette feature
- ability to edit multiple objects at once without having to join meshes (select multiple objects, maybe something like shift tab to enter "edit selected meshes" mode)
Just some thoughts.
Thanks to all the programmers and people who make Blender possible. Your work is deeply appreciated and simply incredible!!
RobertT